# File lib/sequel/database/schema_methods.rb 909 def primary_key_constraint_sql_fragment(_) 910 'PRIMARY KEY' 911 end
class Sequel::Database
A Database
object represents a virtual connection to a database. The Database
class is meant to be subclassed by database adapters in order to provide the functionality needed for executing queries.
Constants
- OPTS
1 - Methods that execute queries and/or return results
↑ topConstants
- COLUMN_SCHEMA_DATETIME_TYPES
- COLUMN_SCHEMA_STRING_TYPES
Attributes
Whether the schema should be cached for this database. True by default for performance, can be set to false to always issue a database query to get the schema.
The prepared statement object hash for this database, keyed by name symbol
Public Instance Methods
Runs the supplied SQL statement string on the database server. Returns self so it can be safely chained:
DB << "UPDATE albums SET artist_id = NULL" << "DROP TABLE artists"
# File lib/sequel/database/query.rb 25 def <<(sql) 26 run(sql) 27 self 28 end
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].where(id: 1).prepare(:first, :sa) DB.call(:sa) # SELECT * FROM items WHERE id = 1
# File lib/sequel/database/query.rb 35 def call(ps_name, hash=OPTS, &block) 36 prepared_statement(ps_name).call(hash, &block) 37 end
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as create_table
. By default, calls execute_dui
. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 42 def execute_ddl(sql, opts=OPTS, &block) 43 execute_dui(sql, opts, &block) 44 end
Method that should be used when issuing a DELETE or UPDATE statement. By default, calls execute. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 49 def execute_dui(sql, opts=OPTS, &block) 50 execute(sql, opts, &block) 51 end
Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 56 def execute_insert(sql, opts=OPTS, &block) 57 execute_dui(sql, opts, &block) 58 end
Returns a single value from the database, see Dataset#get.
DB.get(1) # SELECT 1 # => 1 DB.get{server_version.function} # SELECT server_version()
# File lib/sequel/database/query.rb 65 def get(*args, &block) 66 @default_dataset.get(*args, &block) 67 end
Runs the supplied SQL statement string on the database server. Returns nil. Options:
- :server
-
The server to run the SQL on.
DB.run("SET some_server_variable = 42")
# File lib/sequel/database/query.rb 74 def run(sql, opts=OPTS) 75 sql = literal(sql) if sql.is_a?(SQL::PlaceholderLiteralString) 76 execute_ddl(sql, opts) 77 nil 78 end
Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. The table argument can also be a dataset, as long as it only has one table. Available options are:
- :reload
-
Ignore any cached results, and get fresh information from the database.
- :schema
-
An explicit schema to use. It may also be implicitly provided via the table name.
If schema parsing is supported by the database, the column information hash should contain at least the following entries:
- :allow_null
-
Whether NULL is an allowed value for the column.
- :db_type
-
The database type for the column, as a database specific string.
- :default
-
The database default for the column, as a database specific string, or nil if there is no default value.
- :primary_key
-
Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key.
- :ruby_default
-
The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value.
- :type
-
A symbol specifying the type, such as :integer or :string.
Example:
DB.schema(:artists) # [[:id, # {:type=>:integer, # :primary_key=>true, # :default=>"nextval('artist_id_seq'::regclass)", # :ruby_default=>nil, # :db_type=>"integer", # :allow_null=>false}], # [:name, # {:type=>:string, # :primary_key=>false, # :default=>nil, # :ruby_default=>nil, # :db_type=>"text", # :allow_null=>false}]]
# File lib/sequel/database/query.rb 121 def schema(table, opts=OPTS) 122 raise(Error, 'schema parsing is not implemented on this database') unless supports_schema_parsing? 123 124 opts = opts.dup 125 tab = if table.is_a?(Dataset) 126 o = table.opts 127 from = o[:from] 128 raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql) 129 table.first_source_table 130 else 131 table 132 end 133 134 qualifiers = split_qualifiers(tab) 135 table_name = qualifiers.pop 136 sch = qualifiers.pop 137 information_schema_schema = case qualifiers.length 138 when 1 139 Sequel.identifier(*qualifiers) 140 when 2 141 Sequel.qualify(*qualifiers) 142 end 143 144 if table.is_a?(Dataset) 145 quoted_name = table.literal(tab) 146 opts[:dataset] = table 147 else 148 quoted_name = schema_utility_dataset.literal(table) 149 end 150 151 opts[:schema] = sch if sch && !opts.include?(:schema) 152 opts[:information_schema_schema] = information_schema_schema if information_schema_schema && !opts.include?(:information_schema_schema) 153 154 Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload] 155 if v = Sequel.synchronize{@schemas[quoted_name]} 156 return v 157 end 158 159 cols = schema_parse_table(table_name, opts) 160 raise(Error, "schema parsing returned no columns, table #{table_name.inspect} probably doesn't exist") if cols.nil? || cols.empty? 161 162 primary_keys = 0 163 auto_increment_set = false 164 cols.each do |_,c| 165 auto_increment_set = true if c.has_key?(:auto_increment) 166 primary_keys += 1 if c[:primary_key] 167 end 168 169 cols.each do |_,c| 170 c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type]) unless c.has_key?(:ruby_default) 171 if c[:primary_key] && !auto_increment_set 172 # If adapter didn't set it, assume that integer primary keys are auto incrementing 173 c[:auto_increment] = primary_keys == 1 && !!(c[:db_type] =~ /int/io) 174 end 175 if !c[:max_length] && c[:type] == :string && (max_length = column_schema_max_length(c[:db_type])) 176 c[:max_length] = max_length 177 end 178 end 179 schema_post_process(cols) 180 181 Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema 182 cols 183 end
Returns true if a table with the given name exists. This requires a query to the database.
DB.table_exists?(:foo) # => false # SELECT NULL FROM foo LIMIT 1
Note that since this does a SELECT from the table, it can give false negatives if you don’t have permission to SELECT from the table.
# File lib/sequel/database/query.rb 193 def table_exists?(name) 194 sch, table_name = schema_and_table(name) 195 name = SQL::QualifiedIdentifier.new(sch, table_name) if sch 196 ds = from(name) 197 transaction(:savepoint=>:only){_table_exists?(ds)} 198 true 199 rescue DatabaseError 200 false 201 end
Private Instance Methods
Uncached version of metadata_dataset
, designed for overriding.
# File lib/sequel/database/query.rb 291 def _metadata_dataset 292 dataset 293 end
Should raise an error if the table doesn’t not exist, and not raise an error if the table does exist.
# File lib/sequel/database/query.rb 207 def _table_exists?(ds) 208 ds.get(SQL::AliasedExpression.new(Sequel::NULL, :nil)) 209 end
Whether the type should be treated as a string type when parsing the column schema default value.
# File lib/sequel/database/query.rb 213 def column_schema_default_string_type?(type) 214 COLUMN_SCHEMA_STRING_TYPES.include?(type) 215 end
Transform the given normalized default string into a ruby object for the given type.
# File lib/sequel/database/query.rb 219 def column_schema_default_to_ruby_value(default, type) 220 case type 221 when :boolean 222 case default 223 when /[f0]/i 224 false 225 when /[t1]/i 226 true 227 end 228 when :string, :enum, :set, :interval 229 default 230 when :blob 231 Sequel::SQL::Blob.new(default) 232 when :integer 233 Integer(default) 234 when :float 235 Float(default) 236 when :date 237 Sequel.string_to_date(default) 238 when :datetime 239 Sequel.string_to_datetime(default) 240 when :time 241 Sequel.string_to_time(default) 242 when :decimal 243 BigDecimal(default) 244 end 245 end
Look at the db_type and guess the maximum length of the column. This assumes types such as varchar(255).
# File lib/sequel/database/query.rb 277 def column_schema_max_length(db_type) 278 if db_type =~ /\((\d+)\)/ 279 $1.to_i 280 end 281 end
Normalize the default value string for the given type and return the normalized value.
# File lib/sequel/database/query.rb 249 def column_schema_normalize_default(default, type) 250 if column_schema_default_string_type?(type) 251 return unless m = /\A'(.*)'\z/.match(default) 252 m[1].gsub("''", "'") 253 else 254 default 255 end 256 end
Convert the given default, which should be a database specific string, into a ruby object.
# File lib/sequel/database/query.rb 260 def column_schema_to_ruby_default(default, type) 261 return default unless default.is_a?(String) 262 if COLUMN_SCHEMA_DATETIME_TYPES.include?(type) 263 if /now|today|CURRENT|getdate|\ADate\(\)\z/i.match(default) 264 if type == :date 265 return Sequel::CURRENT_DATE 266 else 267 return Sequel::CURRENT_TIMESTAMP 268 end 269 end 270 end 271 default = column_schema_normalize_default(default, type) 272 column_schema_default_to_ruby_value(default, type) rescue nil 273 end
Return a Method object for the dataset’s output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 286 def input_identifier_meth(ds=nil) 287 (ds || dataset).method(:input_identifier) 288 end
Return a dataset that uses the default identifier input and output methods for this database. Used when parsing metadata so that column symbols are returned as expected.
# File lib/sequel/database/query.rb 298 def metadata_dataset 299 @metadata_dataset ||= _metadata_dataset 300 end
Return a Method object for the dataset’s output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 305 def output_identifier_meth(ds=nil) 306 (ds || dataset).method(:output_identifier) 307 end
Remove the cached schema for the given schema name
# File lib/sequel/database/query.rb 310 def remove_cached_schema(table) 311 cache = @default_dataset.send(:cache) 312 Sequel.synchronize{cache.clear} 313 k = quote_schema_table(table) 314 Sequel.synchronize{@schemas.delete(k)} 315 end
Match the database’s column type to a ruby type via a regular expression, and return the ruby type as a symbol such as :integer or :string.
# File lib/sequel/database/query.rb 320 def schema_column_type(db_type) 321 case db_type 322 when /\A(character( varying)?|n?(var)?char|n?text|string|clob)/io 323 :string 324 when /\A(int(eger)?|(big|small|tiny)int)/io 325 :integer 326 when /\Adate\z/io 327 :date 328 when /\A((small)?datetime|timestamp(\(\d\))?( with(out)? time zone)?)\z/io 329 :datetime 330 when /\Atime( with(out)? time zone)?\z/io 331 :time 332 when /\A(bool(ean)?)\z/io 333 :boolean 334 when /\A(real|float( unsigned)?|double( precision)?|double\(\d+,\d+\)( unsigned)?)\z/io 335 :float 336 when /\A(?:(?:(?:num(?:ber|eric)?|decimal)(?:\(\d+,\s*(\d+|false|true)\))?))\z/io 337 $1 && ['0', 'false'].include?($1) ? :integer : :decimal 338 when /bytea|blob|image|(var)?binary/io 339 :blob 340 when /\Aenum/io 341 :enum 342 end 343 end
Post process the schema values.
# File lib/sequel/database/query.rb 346 def schema_post_process(cols) 347 # :nocov: 348 if RUBY_VERSION >= '2.5' 349 # :nocov: 350 cols.each do |_, h| 351 db_type = h[:db_type] 352 if db_type.is_a?(String) 353 h[:db_type] = -db_type 354 end 355 end 356 end 357 358 cols.each do |_,c| 359 c.each_value do |val| 360 val.freeze if val.is_a?(String) 361 end 362 end 363 end
2 - Methods that modify the database schema
↑ topConstants
- COLUMN_DEFINITION_ORDER
The order of column modifiers to use when defining a column.
- COMBINABLE_ALTER_TABLE_OPS
The alter table operations that are combinable.
Public Instance Methods
Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:
DB.add_column :items, :name, String, unique: true, null: false DB.add_column :items, :category, String, default: 'ruby'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 25 def add_column(table, *args) 26 alter_table(table) {add_column(*args)} 27 end
Adds an index to a table for the given columns:
DB.add_index :posts, :title DB.add_index :posts, [:author, :title], unique: true
Options:
- :ignore_errors
-
Ignore any DatabaseErrors that are raised
- :name
-
Name to use for index instead of default
See alter_table
.
# File lib/sequel/database/schema_methods.rb 40 def add_index(table, columns, options=OPTS) 41 e = options[:ignore_errors] 42 begin 43 alter_table(table){add_index(columns, options)} 44 rescue DatabaseError 45 raise unless e 46 end 47 nil 48 end
Alters the given table with the specified block. Example:
DB.alter_table :items do add_column :category, String, default: 'ruby' drop_column :category rename_column :cntr, :counter set_column_type :value, Float set_column_default :value, 4.2 add_index [:group, :category] drop_index [:group, :category] end
Note that add_column
accepts all the options available for column definitions using create_table
, and add_index
accepts all the options available for index definition.
See Schema::AlterTableGenerator
and the Migrations guide.
# File lib/sequel/database/schema_methods.rb 67 def alter_table(name, &block) 68 generator = alter_table_generator(&block) 69 remove_cached_schema(name) 70 apply_alter_table_generator(name, generator) 71 nil 72 end
Return a new Schema::AlterTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 76 def alter_table_generator(&block) 77 alter_table_generator_class.new(self, &block) 78 end
Create a join table using a hash of foreign keys to referenced table names. Example:
create_join_table(cat_id: :cats, dog_id: :dogs) # CREATE TABLE cats_dogs ( # cat_id integer NOT NULL REFERENCES cats, # dog_id integer NOT NULL REFERENCES dogs, # PRIMARY KEY (cat_id, dog_id) # ) # CREATE INDEX cats_dogs_dog_id_cat_id_index ON cats_dogs(dog_id, cat_id)
The primary key and index are used so that almost all operations on the table can benefit from one of the two indexes, and the primary key ensures that entries in the table are unique, which is the typical desire for a join table.
The default table name this will create is the sorted version of the two hash values, joined by an underscore. So the following two method calls create the same table:
create_join_table(cat_id: :cats, dog_id: :dogs) # cats_dogs create_join_table(dog_id: :dogs, cat_id: :cats) # cats_dogs
You can provide column options by making the values in the hash be option hashes, so long as the option hashes have a :table entry giving the table referenced:
create_join_table(cat_id: {table: :cats, type: :Bignum}, dog_id: :dogs)
You can provide a second argument which is a table options hash:
create_join_table({cat_id: :cats, dog_id: :dogs}, temp: true)
Some table options are handled specially:
- :index_options
-
The options to pass to the index
- :name
-
The name of the table to create
- :no_index
-
Set to true not to create the second index.
- :no_primary_key
-
Set to true to not create the primary key.
# File lib/sequel/database/schema_methods.rb 119 def create_join_table(hash, options=OPTS) 120 keys = hash.keys.sort 121 create_table(join_table_name(hash, options), options) do 122 keys.each do |key| 123 v = hash[key] 124 unless v.is_a?(Hash) 125 v = {:table=>v} 126 end 127 v[:null] = false unless v.has_key?(:null) 128 foreign_key(key, v) 129 end 130 primary_key(keys) unless options[:no_primary_key] 131 index(keys.reverse, options[:index_options] || OPTS) unless options[:no_index] 132 end 133 nil 134 end
Forcibly create a join table, attempting to drop it if it already exists, then creating it.
# File lib/sequel/database/schema_methods.rb 137 def create_join_table!(hash, options=OPTS) 138 drop_table?(join_table_name(hash, options)) 139 create_join_table(hash, options) 140 end
Creates the join table unless it already exists.
# File lib/sequel/database/schema_methods.rb 143 def create_join_table?(hash, options=OPTS) 144 if supports_create_table_if_not_exists? && options[:no_index] 145 create_join_table(hash, options.merge(:if_not_exists=>true)) 146 elsif !table_exists?(join_table_name(hash, options)) 147 create_join_table(hash, options) 148 end 149 end
Creates a view, replacing a view with the same name if one already exists.
DB.create_or_replace_view(:some_items, "SELECT * FROM items WHERE price < 100") DB.create_or_replace_view(:some_items, DB[:items].where(category: 'ruby'))
For databases where replacing a view is not natively supported, support is emulated by dropping a view with the same name before creating the view.
# File lib/sequel/database/schema_methods.rb 248 def create_or_replace_view(name, source, options = OPTS) 249 if supports_create_or_replace_view? 250 options = options.merge(:replace=>true) 251 else 252 swallow_database_error{drop_view(name)} 253 end 254 255 create_view(name, source, options) 256 nil 257 end
Creates a table with the columns given in the provided block:
DB.create_table :posts do primary_key :id column :title, String String :content index :title end
General options:
- :as
-
Create the table using the value, which should be either a dataset or a literal SQL string. If this option is used, a block should not be given to the method.
- :ignore_index_errors
-
Ignore any errors when creating indexes.
- :temp
-
Create the table as a temporary table.
MySQL specific options:
- :charset
-
The character set to use for the table.
- :collate
-
The collation to use for the table.
- :engine
-
The table engine to use for the table.
PostgreSQL specific options:
- :on_commit
-
Either :preserve_rows (default), :drop or :delete_rows. Should only be specified when creating a temporary table.
- :foreign
-
Create a foreign table. The value should be the name of the foreign server that was specified in CREATE SERVER.
- :inherits
-
Inherit from a different table. An array can be specified to inherit from multiple tables.
- :unlogged
-
Create the table as an unlogged table.
- :options
-
The OPTIONS clause to use for foreign tables. Should be a hash where keys are option names and values are option values. Note that option names are unquoted, so you should not use untrusted keys.
- :tablespace
-
The tablespace to use for the table.
SQLite specific options:
- :strict
-
Create a STRICT table, which checks that the values for the columns are the correct type (similar to all other SQL databases). Note that when using this option, all column types used should be one of the following:
int
,integer
,real
,text
,blob
, andany
. Theany
type is treated like a SQLite column in a non-strict table, allowing any type of data to be stored. This option is supported on SQLite 3.37.0+.
See Schema::CreateTableGenerator
and the “Schema Modification” guide.
# File lib/sequel/database/schema_methods.rb 196 def create_table(name, options=OPTS, &block) 197 remove_cached_schema(name) 198 if sql = options[:as] 199 raise(Error, "can't provide both :as option and block to create_table") if block 200 create_table_as(name, sql, options) 201 else 202 generator = options[:generator] || create_table_generator(&block) 203 create_table_from_generator(name, generator, options) 204 create_table_indexes_from_generator(name, generator, options) 205 end 206 nil 207 end
Forcibly create a table, attempting to drop it if it already exists, then creating it.
DB.create_table!(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- drop table if already exists # CREATE TABLE a (a integer)
# File lib/sequel/database/schema_methods.rb 215 def create_table!(name, options=OPTS, &block) 216 drop_table?(name) 217 create_table(name, options, &block) 218 end
Creates the table unless the table already exists.
DB.create_table?(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # CREATE TABLE a (a integer) -- if it doesn't already exist
# File lib/sequel/database/schema_methods.rb 225 def create_table?(name, options=OPTS, &block) 226 options = options.dup 227 generator = options[:generator] ||= create_table_generator(&block) 228 if generator.indexes.empty? && supports_create_table_if_not_exists? 229 create_table(name, options.merge!(:if_not_exists=>true)) 230 elsif !table_exists?(name) 231 create_table(name, options) 232 end 233 end
Return a new Schema::CreateTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 237 def create_table_generator(&block) 238 create_table_generator_class.new(self, &block) 239 end
Creates a view based on a dataset or an SQL string:
DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100") # CREATE VIEW cheap_items AS # SELECT * FROM items WHERE price < 100 DB.create_view(:ruby_items, DB[:items].where(category: 'ruby')) # CREATE VIEW ruby_items AS # SELECT * FROM items WHERE (category = 'ruby') DB.create_view(:checked_items, DB[:items].where(:foo), check: true) # CREATE VIEW checked_items AS # SELECT * FROM items WHERE foo # WITH CHECK OPTION DB.create_view(:bar_items, DB[:items].select(:foo), columns: [:bar]) # CREATE VIEW bar_items (bar) AS # SELECT foo FROM items
Options:
- :columns
-
The column names to use for the view. If not given, automatically determined based on the input dataset.
- :check
-
Adds a WITH CHECK OPTION clause, so that attempting to modify rows in the underlying table that would not be returned by the view is not allowed. This can be set to :local to use WITH LOCAL CHECK OPTION.
PostgreSQL/SQLite specific option:
- :temp
-
Create a temporary view, automatically dropped on disconnect.
PostgreSQL specific options:
- :materialized
-
Creates a materialized view, similar to a regular view, but backed by a physical table.
- :recursive
-
Creates a recursive view. As columns must be specified for recursive views, you can also set them as the value of this option. Since a recursive view requires a union that isn’t in a subquery, if you are providing a Dataset as the source argument, if should probably call the union method with the all: true and from_self: false options.
- :tablespace
-
The tablespace to use for materialized views.
# File lib/sequel/database/schema_methods.rb 299 def create_view(name, source, options = OPTS) 300 execute_ddl(create_view_sql(name, source, options)) 301 remove_cached_schema(name) 302 nil 303 end
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table
.
# File lib/sequel/database/schema_methods.rb 310 def drop_column(table, *args) 311 alter_table(table) {drop_column(*args)} 312 end
Removes an index for the given table and column(s):
DB.drop_index :posts, :title DB.drop_index :posts, [:author, :title]
See alter_table
.
# File lib/sequel/database/schema_methods.rb 320 def drop_index(table, columns, options=OPTS) 321 alter_table(table){drop_index(columns, options)} 322 end
Drop the join table that would have been created with the same arguments to create_join_table
:
drop_join_table(cat_id: :cats, dog_id: :dogs) # DROP TABLE cats_dogs
# File lib/sequel/database/schema_methods.rb 329 def drop_join_table(hash, options=OPTS) 330 drop_table(join_table_name(hash, options), options) 331 end
Drops one or more tables corresponding to the given names:
DB.drop_table(:posts) # DROP TABLE posts DB.drop_table(:posts, :comments) DB.drop_table(:posts, :comments, cascade: true)
# File lib/sequel/database/schema_methods.rb 338 def drop_table(*names) 339 options = names.last.is_a?(Hash) ? names.pop : OPTS 340 names.each do |n| 341 execute_ddl(drop_table_sql(n, options)) 342 remove_cached_schema(n) 343 end 344 nil 345 end
Drops the table if it already exists. If it doesn’t exist, does nothing.
DB.drop_table?(:a) # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- if it already exists
# File lib/sequel/database/schema_methods.rb 353 def drop_table?(*names) 354 options = names.last.is_a?(Hash) ? names.pop : OPTS 355 if supports_drop_table_if_exists? 356 options = options.merge(:if_exists=>true) 357 names.each do |name| 358 drop_table(name, options) 359 end 360 else 361 names.each do |name| 362 drop_table(name, options) if table_exists?(name) 363 end 364 end 365 nil 366 end
Drops one or more views corresponding to the given names:
DB.drop_view(:cheap_items) DB.drop_view(:cheap_items, :pricey_items) DB.drop_view(:cheap_items, :pricey_items, cascade: true) DB.drop_view(:cheap_items, :pricey_items, if_exists: true)
Options:
- :cascade
-
Also drop objects depending on this view.
- :if_exists
-
Do not raise an error if the view does not exist.
PostgreSQL specific options:
- :materialized
-
Drop a materialized view.
# File lib/sequel/database/schema_methods.rb 381 def drop_view(*names) 382 options = names.last.is_a?(Hash) ? names.pop : OPTS 383 names.each do |n| 384 execute_ddl(drop_view_sql(n, options)) 385 remove_cached_schema(n) 386 end 387 nil 388 end
Renames a column in the specified table. This method expects the current column name and the new column name:
DB.rename_column :items, :cntr, :counter
See alter_table
.
# File lib/sequel/database/schema_methods.rb 407 def rename_column(table, *args) 408 alter_table(table) {rename_column(*args)} 409 end
Renames a table:
DB.tables #=> [:items] DB.rename_table :items, :old_items DB.tables #=> [:old_items]
# File lib/sequel/database/schema_methods.rb 395 def rename_table(name, new_name) 396 execute_ddl(rename_table_sql(name, new_name)) 397 remove_cached_schema(name) 398 nil 399 end
Sets the default value for the given column in the given table:
DB.set_column_default :items, :category, 'perl!'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 416 def set_column_default(table, *args) 417 alter_table(table) {set_column_default(*args)} 418 end
Set the data type for the given column in the given table:
DB.set_column_type :items, :price, :float
See alter_table
.
# File lib/sequel/database/schema_methods.rb 425 def set_column_type(table, *args) 426 alter_table(table) {set_column_type(*args)} 427 end
Private Instance Methods
# File lib/sequel/database/schema_methods.rb 465 def alter_table_add_column_sql(table, op) 466 "ADD COLUMN #{column_definition_sql(op)}" 467 end
# File lib/sequel/database/schema_methods.rb 489 def alter_table_add_constraint_sql(table, op) 490 "ADD #{constraint_definition_sql(op)}" 491 end
# File lib/sequel/database/schema_methods.rb 469 def alter_table_drop_column_sql(table, op) 470 "DROP COLUMN #{quote_identifier(op[:name])}#{' CASCADE' if op[:cascade]}" 471 end
# File lib/sequel/database/schema_methods.rb 493 def alter_table_drop_constraint_sql(table, op) 494 quoted_name = quote_identifier(op[:name]) if op[:name] 495 if op[:type] == :foreign_key 496 quoted_name ||= quote_identifier(foreign_key_name(table, op[:columns])) 497 end 498 "DROP CONSTRAINT #{quoted_name}#{' CASCADE' if op[:cascade]}" 499 end
The class used for alter_table
generators.
# File lib/sequel/database/schema_methods.rb 450 def alter_table_generator_class 451 Schema::AlterTableGenerator 452 end
SQL fragment for given alter table operation.
# File lib/sequel/database/schema_methods.rb 455 def alter_table_op_sql(table, op) 456 meth = "alter_table_#{op[:op]}_sql" 457 if respond_to?(meth, true) 458 # Allow calling private methods as alter table op sql methods are private 459 send(meth, table, op) 460 else 461 raise Error, "Unsupported ALTER TABLE operation: #{op[:op]}" 462 end 463 end
# File lib/sequel/database/schema_methods.rb 473 def alter_table_rename_column_sql(table, op) 474 "RENAME COLUMN #{quote_identifier(op[:name])} TO #{quote_identifier(op[:new_name])}" 475 end
# File lib/sequel/database/schema_methods.rb 481 def alter_table_set_column_default_sql(table, op) 482 "ALTER COLUMN #{quote_identifier(op[:name])} SET DEFAULT #{literal(op[:default])}" 483 end
# File lib/sequel/database/schema_methods.rb 485 def alter_table_set_column_null_sql(table, op) 486 "ALTER COLUMN #{quote_identifier(op[:name])} #{op[:null] ? 'DROP' : 'SET'} NOT NULL" 487 end
# File lib/sequel/database/schema_methods.rb 477 def alter_table_set_column_type_sql(table, op) 478 "ALTER COLUMN #{quote_identifier(op[:name])} TYPE #{type_literal(op)}" 479 end
The SQL to execute to modify the table. op should be one of the operations returned by the AlterTableGenerator.
# File lib/sequel/database/schema_methods.rb 503 def alter_table_sql(table, op) 504 case op[:op] 505 when :add_index 506 index_definition_sql(table, op) 507 when :drop_index 508 drop_index_sql(table, op) 509 else 510 if sql = alter_table_op_sql(table, op) 511 "ALTER TABLE #{quote_schema_table(table)} #{sql}" 512 end 513 end 514 end
Array
of SQL statements used to modify the table, corresponding to changes specified by the operations.
# File lib/sequel/database/schema_methods.rb 518 def alter_table_sql_list(table, operations) 519 if supports_combining_alter_table_ops? 520 grouped_ops = [] 521 last_combinable = false 522 operations.each do |op| 523 if combinable_alter_table_op?(op) 524 if sql = alter_table_op_sql(table, op) 525 grouped_ops << [] unless last_combinable 526 grouped_ops.last << sql 527 last_combinable = true 528 end 529 elsif sql = alter_table_sql(table, op) 530 Array(sql).each{|s| grouped_ops << s} 531 last_combinable = false 532 end 533 end 534 grouped_ops.map do |gop| 535 if gop.is_a?(Array) 536 "ALTER TABLE #{quote_schema_table(table)} #{gop.join(', ')}" 537 else 538 gop 539 end 540 end 541 else 542 operations.map{|op| alter_table_sql(table, op)}.flatten.compact 543 end 544 end
Apply the changes in the given alter table ops to the table given by name.
# File lib/sequel/database/schema_methods.rb 432 def apply_alter_table(name, ops) 433 alter_table_sql_list(name, ops).each{|sql| execute_ddl(sql)} 434 end
Apply the operations in the given generator to the table given by name.
# File lib/sequel/database/schema_methods.rb 437 def apply_alter_table_generator(name, generator) 438 ops = generator.operations 439 440 unless can_add_primary_key_constraint_on_nullable_columns? 441 if add_pk = ops.find{|op| op[:op] == :add_constraint && op[:type] == :primary_key} 442 ops = add_pk[:columns].map{|column| {:op => :set_column_null, :name => column, :null => false}} + ops 443 end 444 end 445 446 apply_alter_table(name, ops) 447 end
The SQL string specify the autoincrement property, generally used by primary keys.
# File lib/sequel/database/schema_methods.rb 548 def auto_increment_sql 549 'AUTOINCREMENT' 550 end
Add auto increment SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 566 def column_definition_auto_increment_sql(sql, column) 567 sql << " #{auto_increment_sql}" if column[:auto_increment] 568 end
Add collate SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 571 def column_definition_collate_sql(sql, column) 572 if collate = column[:collate] 573 sql << " COLLATE #{collate}" 574 end 575 end
Add default SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 578 def column_definition_default_sql(sql, column) 579 sql << " DEFAULT #{literal(column[:default])}" if column.include?(:default) 580 end
Add null/not null SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 583 def column_definition_null_sql(sql, column) 584 null = column.fetch(:null, column[:allow_null]) 585 if null.nil? && !can_add_primary_key_constraint_on_nullable_columns? && column[:primary_key] 586 null = false 587 end 588 589 case null 590 when false 591 sql << ' NOT NULL' 592 when true 593 sql << ' NULL' 594 end 595 end
The order of the column definition, as an array of symbols.
# File lib/sequel/database/schema_methods.rb 553 def column_definition_order 554 COLUMN_DEFINITION_ORDER 555 end
Add primary key SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 598 def column_definition_primary_key_sql(sql, column) 599 if column[:primary_key] 600 if name = column[:primary_key_constraint_name] 601 sql << " CONSTRAINT #{quote_identifier(name)}" 602 end 603 sql << " " << primary_key_constraint_sql_fragment(column) 604 constraint_deferrable_sql_append(sql, column[:primary_key_deferrable]) 605 end 606 end
Add foreign key reference SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 609 def column_definition_references_sql(sql, column) 610 if column[:table] 611 if name = column[:foreign_key_constraint_name] 612 sql << " CONSTRAINT #{quote_identifier(name)}" 613 end 614 sql << column_references_column_constraint_sql(column) 615 end 616 end
SQL fragment containing the column creation SQL for the given column.
# File lib/sequel/database/schema_methods.rb 558 def column_definition_sql(column) 559 sql = String.new 560 sql << "#{quote_identifier(column[:name])} #{type_literal(column)}" 561 column_definition_order.each{|m| send(:"column_definition_#{m}_sql", sql, column)} 562 sql 563 end
Add unique constraint SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 619 def column_definition_unique_sql(sql, column) 620 if column[:unique] 621 if name = column[:unique_constraint_name] 622 sql << " CONSTRAINT #{quote_identifier(name)}" 623 end 624 sql << ' ' << unique_constraint_sql_fragment(column) 625 constraint_deferrable_sql_append(sql, column[:unique_deferrable]) 626 end 627 end
SQL for all given columns, used inside a CREATE TABLE block.
# File lib/sequel/database/schema_methods.rb 630 def column_list_sql(generator) 631 (generator.columns.map{|c| column_definition_sql(c)} + generator.constraints.map{|c| constraint_definition_sql(c)}).join(', ') 632 end
SQL fragment for column foreign key references (column constraints)
# File lib/sequel/database/schema_methods.rb 635 def column_references_column_constraint_sql(column) 636 column_references_sql(column) 637 end
SQL fragment for column foreign key references
# File lib/sequel/database/schema_methods.rb 640 def column_references_sql(column) 641 sql = String.new 642 sql << " REFERENCES #{quote_schema_table(column[:table])}" 643 sql << "(#{Array(column[:key]).map{|x| quote_identifier(x)}.join(', ')})" if column[:key] 644 sql << " ON DELETE #{on_delete_clause(column[:on_delete])}" if column[:on_delete] 645 sql << " ON UPDATE #{on_update_clause(column[:on_update])}" if column[:on_update] 646 constraint_deferrable_sql_append(sql, column[:deferrable]) 647 sql 648 end
SQL fragment for table foreign key references (table constraints)
# File lib/sequel/database/schema_methods.rb 651 def column_references_table_constraint_sql(constraint) 652 "FOREIGN KEY #{literal(constraint[:columns])}#{column_references_sql(constraint)}" 653 end
Whether the given alter table operation is combinable.
# File lib/sequel/database/schema_methods.rb 656 def combinable_alter_table_op?(op) 657 COMBINABLE_ALTER_TABLE_OPS.include?(op[:op]) 658 end
SQL fragment specifying the deferrable constraint attributes.
# File lib/sequel/database/schema_methods.rb 685 def constraint_deferrable_sql_append(sql, defer) 686 case defer 687 when nil 688 when false 689 sql << ' NOT DEFERRABLE' 690 when :immediate 691 sql << ' DEFERRABLE INITIALLY IMMEDIATE' 692 else 693 sql << ' DEFERRABLE INITIALLY DEFERRED' 694 end 695 end
SQL fragment specifying a constraint on a table.
# File lib/sequel/database/schema_methods.rb 661 def constraint_definition_sql(constraint) 662 sql = String.new 663 sql << "CONSTRAINT #{quote_identifier(constraint[:name])} " if constraint[:name] 664 case constraint[:type] 665 when :check 666 check = constraint[:check] 667 check = check.first if check.is_a?(Array) && check.length == 1 668 check = filter_expr(check) 669 check = "(#{check})" unless check[0..0] == '(' && check[-1..-1] == ')' 670 sql << "CHECK #{check}" 671 when :primary_key 672 sql << "#{primary_key_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}" 673 when :foreign_key 674 sql << column_references_table_constraint_sql(constraint.merge(:deferrable=>nil)) 675 when :unique 676 sql << "#{unique_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}" 677 else 678 raise Error, "Invalid constraint type #{constraint[:type]}, should be :check, :primary_key, :foreign_key, or :unique" 679 end 680 constraint_deferrable_sql_append(sql, constraint[:deferrable]) 681 sql 682 end
Run SQL statement to create the table with the given name from the given SELECT sql statement.
# File lib/sequel/database/schema_methods.rb 755 def create_table_as(name, sql, options) 756 sql = sql.sql if sql.is_a?(Sequel::Dataset) 757 run(create_table_as_sql(name, sql, options)) 758 end
SQL statement for creating a table from the result of a SELECT statement. sql
should be a string representing a SELECT query.
# File lib/sequel/database/schema_methods.rb 762 def create_table_as_sql(name, sql, options) 763 "#{create_table_prefix_sql(name, options)} AS #{sql}" 764 end
Execute the create table statements using the generator.
# File lib/sequel/database/schema_methods.rb 698 def create_table_from_generator(name, generator, options) 699 execute_ddl(create_table_sql(name, generator, options)) 700 end
The class used for create_table
generators.
# File lib/sequel/database/schema_methods.rb 703 def create_table_generator_class 704 Schema::CreateTableGenerator 705 end
Execute the create index statements using the generator.
# File lib/sequel/database/schema_methods.rb 708 def create_table_indexes_from_generator(name, generator, options) 709 e = options[:ignore_index_errors] || options[:if_not_exists] 710 generator.indexes.each do |index| 711 begin 712 pr = proc{index_sql_list(name, [index]).each{|sql| execute_ddl(sql)}} 713 supports_transactional_ddl? ? transaction(:savepoint=>:only, &pr) : pr.call 714 rescue Error 715 raise unless e 716 end 717 end 718 end
SQL fragment for initial part of CREATE TABLE statement
# File lib/sequel/database/schema_methods.rb 767 def create_table_prefix_sql(name, options) 768 "CREATE #{temporary_table_sql if options[:temp]}TABLE#{' IF NOT EXISTS' if options[:if_not_exists]} #{options[:temp] ? quote_identifier(name) : quote_schema_table(name)}" 769 end
SQL statement for creating a table with the given name, columns, and options
# File lib/sequel/database/schema_methods.rb 721 def create_table_sql(name, generator, options) 722 unless supports_named_column_constraints? 723 # Split column constraints into table constraints if they have a name 724 generator.columns.each do |c| 725 if (constraint_name = c.delete(:foreign_key_constraint_name)) && (table = c.delete(:table)) 726 opts = {} 727 opts[:name] = constraint_name 728 [:key, :on_delete, :on_update, :deferrable].each{|k| opts[k] = c[k]} 729 generator.foreign_key([c[:name]], table, opts) 730 end 731 if (constraint_name = c.delete(:unique_constraint_name)) && c.delete(:unique) 732 generator.unique(c[:name], :name=>constraint_name) 733 end 734 if (constraint_name = c.delete(:primary_key_constraint_name)) && c.delete(:primary_key) 735 generator.primary_key([c[:name]], :name=>constraint_name) 736 end 737 end 738 end 739 740 unless can_add_primary_key_constraint_on_nullable_columns? 741 if pk = generator.constraints.find{|op| op[:type] == :primary_key} 742 pk[:columns].each do |column| 743 if matched_column = generator.columns.find{|gc| gc[:name] == column} 744 matched_column[:null] = false 745 end 746 end 747 end 748 end 749 750 "#{create_table_prefix_sql(name, options)} (#{column_list_sql(generator)})" 751 end
SQL fragment for initial part of CREATE VIEW statement
# File lib/sequel/database/schema_methods.rb 772 def create_view_prefix_sql(name, options) 773 create_view_sql_append_columns("CREATE #{'OR REPLACE 'if options[:replace]}VIEW #{quote_schema_table(name)}", options[:columns]) 774 end
SQL statement for creating a view.
# File lib/sequel/database/schema_methods.rb 777 def create_view_sql(name, source, options) 778 source = source.sql if source.is_a?(Dataset) 779 sql = String.new 780 sql << "#{create_view_prefix_sql(name, options)} AS #{source}" 781 if check = options[:check] 782 sql << " WITH#{' LOCAL' if check == :local} CHECK OPTION" 783 end 784 sql 785 end
Append the column list to the SQL, if a column list is given.
# File lib/sequel/database/schema_methods.rb 788 def create_view_sql_append_columns(sql, columns) 789 if columns 790 sql += ' (' 791 schema_utility_dataset.send(:identifier_list_append, sql, columns) 792 sql << ')' 793 end 794 sql 795 end
Default index name for the table and columns, may be too long for certain databases.
# File lib/sequel/database/schema_methods.rb 799 def default_index_name(table_name, columns) 800 schema, table = schema_and_table(table_name) 801 "#{"#{schema}_" if schema}#{table}_#{columns.map{|c| [String, Symbol].any?{|cl| c.is_a?(cl)} ? c : literal(c).gsub(/\W/, '_')}.join('_')}_index" 802 end
The SQL to drop an index for the table.
# File lib/sequel/database/schema_methods.rb 812 def drop_index_sql(table, op) 813 "DROP INDEX #{quote_identifier(op[:name] || default_index_name(table, op[:columns]))}" 814 end
SQL DDL statement to drop the table with the given name.
# File lib/sequel/database/schema_methods.rb 817 def drop_table_sql(name, options) 818 "DROP TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 819 end
SQL DDL statement to drop a view with the given name.
# File lib/sequel/database/schema_methods.rb 822 def drop_view_sql(name, options) 823 "DROP VIEW#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 824 end
Proxy the filter_expr
call to the dataset, used for creating constraints. Support passing Proc arguments as blocks, as well as treating plain strings as literal strings, so that previous migrations that used this API do not break.
# File lib/sequel/database/schema_methods.rb 829 def filter_expr(arg=nil, &block) 830 if arg.is_a?(Proc) && !block 831 block = arg 832 arg = nil 833 elsif arg.is_a?(String) 834 arg = Sequel.lit(arg) 835 elsif arg.is_a?(Array) 836 if arg.first.is_a?(String) 837 arg = Sequel.lit(*arg) 838 elsif arg.length > 1 839 arg = Sequel.&(*arg) 840 end 841 end 842 schema_utility_dataset.literal(schema_utility_dataset.send(:filter_expr, arg, &block)) 843 end
Get foreign key name for given table and columns.
# File lib/sequel/database/schema_methods.rb 805 def foreign_key_name(table_name, columns) 806 keys = foreign_key_list(table_name).select{|key| key[:columns] == columns} 807 raise(Error, "#{keys.empty? ? 'Missing' : 'Ambiguous'} foreign key for #{columns.inspect}") unless keys.size == 1 808 keys.first[:name] 809 end
SQL statement for creating an index for the table with the given name and index specifications.
# File lib/sequel/database/schema_methods.rb 847 def index_definition_sql(table_name, index) 848 index_name = index[:name] || default_index_name(table_name, index[:columns]) 849 raise Error, "Index types are not supported for this database" if index[:type] 850 raise Error, "Partial indexes are not supported for this database" if index[:where] && !supports_partial_indexes? 851 "CREATE #{'UNIQUE ' if index[:unique]}INDEX #{quote_identifier(index_name)} ON #{quote_schema_table(table_name)} #{literal(index[:columns])}#{" WHERE #{filter_expr(index[:where])}" if index[:where]}" 852 end
Array
of SQL statements, one for each index specification, for the given table.
# File lib/sequel/database/schema_methods.rb 856 def index_sql_list(table_name, indexes) 857 indexes.map{|i| index_definition_sql(table_name, i)} 858 end
Extract the join table name from the arguments given to create_join_table. Also does argument validation for the create_join_table
method.
# File lib/sequel/database/schema_methods.rb 862 def join_table_name(hash, options) 863 entries = hash.values 864 raise Error, "must have 2 entries in hash given to (create|drop)_join_table" unless entries.length == 2 865 if options[:name] 866 options[:name] 867 else 868 table_names = entries.map{|e| join_table_name_extract(e)} 869 table_names.map(&:to_s).sort.join('_') 870 end 871 end
Extract an individual join table name, which should either be a string or symbol, or a hash containing one of those as the value for :table.
# File lib/sequel/database/schema_methods.rb 875 def join_table_name_extract(entry) 876 case entry 877 when Symbol, String 878 entry 879 when Hash 880 join_table_name_extract(entry[:table]) 881 else 882 raise Error, "can't extract table name from #{entry.inspect}" 883 end 884 end
SQL fragment to use for ON DELETE, based on the given action. The following actions are recognized:
- :cascade
-
Delete rows referencing this row.
- :no_action
-
Raise an error if other rows reference this row, allow deferring of the integrity check. This is the default.
- :restrict
-
Raise an error if other rows reference this row, but do not allow deferring the integrity check.
- :set_default
-
Set columns referencing this row to their default value.
- :set_null
-
Set columns referencing this row to NULL.
Any other object given is just converted to a string, with “_” converted to “ ” and upcased.
# File lib/sequel/database/schema_methods.rb 899 def on_delete_clause(action) 900 action.to_s.gsub("_", " ").upcase 901 end
Alias of on_delete_clause
, since the two usually behave the same.
# File lib/sequel/database/schema_methods.rb 904 def on_update_clause(action) 905 on_delete_clause(action) 906 end
Add fragment for primary key specification, separated for easier overridding.
Proxy the quote_schema_table
method to the dataset
# File lib/sequel/database/schema_methods.rb 914 def quote_schema_table(table) 915 schema_utility_dataset.quote_schema_table(table) 916 end
SQL statement for renaming a table.
# File lib/sequel/database/schema_methods.rb 919 def rename_table_sql(name, new_name) 920 "ALTER TABLE #{quote_schema_table(name)} RENAME TO #{quote_schema_table(new_name)}" 921 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 924 def schema_and_table(table_name) 925 schema_utility_dataset.schema_and_table(table_name) 926 end
Return true if the given column schema represents an autoincrementing primary key.
# File lib/sequel/database/schema_methods.rb 929 def schema_autoincrementing_primary_key?(schema) 930 !!(schema[:primary_key] && schema[:auto_increment]) 931 end
The dataset to use for proxying certain schema methods.
# File lib/sequel/database/schema_methods.rb 934 def schema_utility_dataset 935 @default_dataset 936 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 939 def split_qualifiers(table_name) 940 schema_utility_dataset.split_qualifiers(table_name) 941 end
SQL fragment for temporary table
# File lib/sequel/database/schema_methods.rb 944 def temporary_table_sql 945 'TEMPORARY ' 946 end
SQL fragment specifying the type of a given column.
# File lib/sequel/database/schema_methods.rb 949 def type_literal(column) 950 case column[:type] 951 when Class 952 type_literal_generic(column) 953 when :Bignum 954 type_literal_generic_bignum_symbol(column) 955 else 956 type_literal_specific(column) 957 end 958 end
SQL fragment specifying the full type of a column, consider the type with possible modifiers.
# File lib/sequel/database/schema_methods.rb 962 def type_literal_generic(column) 963 meth = "type_literal_generic_#{column[:type].name.to_s.downcase}" 964 if respond_to?(meth, true) 965 # Allow calling private methods as per type literal generic methods are private 966 send(meth, column) 967 else 968 raise Error, "Unsupported ruby class used as database type: #{column[:type]}" 969 end 970 end
Alias for type_literal_generic_numeric
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 973 def type_literal_generic_bigdecimal(column) 974 type_literal_generic_numeric(column) 975 end
Sequel
uses the bigint type by default for :Bignum symbol.
# File lib/sequel/database/schema_methods.rb 978 def type_literal_generic_bignum_symbol(column) 979 :bigint 980 end
Sequel
uses the date type by default for Dates.
# File lib/sequel/database/schema_methods.rb 983 def type_literal_generic_date(column) 984 :date 985 end
Sequel
uses the timestamp type by default for DateTimes.
# File lib/sequel/database/schema_methods.rb 988 def type_literal_generic_datetime(column) 989 :timestamp 990 end
Alias for type_literal_generic_trueclass
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 993 def type_literal_generic_falseclass(column) 994 type_literal_generic_trueclass(column) 995 end
Sequel
uses the blob type by default for Files.
# File lib/sequel/database/schema_methods.rb 998 def type_literal_generic_file(column) 999 :blob 1000 end
Alias for type_literal_generic_integer
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 1003 def type_literal_generic_fixnum(column) 1004 type_literal_generic_integer(column) 1005 end
Sequel
uses the double precision type by default for Floats.
# File lib/sequel/database/schema_methods.rb 1008 def type_literal_generic_float(column) 1009 :"double precision" 1010 end
Sequel
uses the integer type by default for integers
# File lib/sequel/database/schema_methods.rb 1013 def type_literal_generic_integer(column) 1014 :integer 1015 end
Sequel
uses the numeric type by default for Numerics and BigDecimals. If a size is given, it is used, otherwise, it will default to whatever the database default is for an unsized value.
# File lib/sequel/database/schema_methods.rb 1020 def type_literal_generic_numeric(column) 1021 column[:size] ? "numeric(#{Array(column[:size]).join(', ')})" : :numeric 1022 end
Use time by default for Time values if :only_time option is used.
# File lib/sequel/database/schema_methods.rb 1049 def type_literal_generic_only_time(column) 1050 :time 1051 end
Sequel
uses the varchar type by default for Strings. If a size isn’t present, Sequel
assumes a size of 255. If the :fixed option is used, Sequel
uses the char type. If the :text option is used, Sequel
uses the :text type.
# File lib/sequel/database/schema_methods.rb 1028 def type_literal_generic_string(column) 1029 if column[:text] 1030 uses_clob_for_text? ? :clob : :text 1031 elsif column[:fixed] 1032 "char(#{column[:size]||default_string_column_size})" 1033 else 1034 "varchar(#{column[:size]||default_string_column_size})" 1035 end 1036 end
Sequel
uses the timestamp type by default for Time values. If the :only_time option is used, the time type is used.
# File lib/sequel/database/schema_methods.rb 1040 def type_literal_generic_time(column) 1041 if column[:only_time] 1042 type_literal_generic_only_time(column) 1043 else 1044 type_literal_generic_datetime(column) 1045 end 1046 end
Sequel
uses the boolean type by default for TrueClass
and FalseClass
.
# File lib/sequel/database/schema_methods.rb 1054 def type_literal_generic_trueclass(column) 1055 :boolean 1056 end
SQL fragment for the given type of a column if the column is not one of the generic types specified with a ruby class.
# File lib/sequel/database/schema_methods.rb 1060 def type_literal_specific(column) 1061 type = column[:type] 1062 type = "double precision" if type.to_s == 'double' 1063 column[:size] ||= default_string_column_size if type.to_s == 'varchar' 1064 elements = column[:size] || column[:elements] 1065 "#{type}#{literal(Array(elements)) if elements}#{' UNSIGNED' if column[:unsigned]}" 1066 end
Add fragment for unique specification, separated for easier overridding.
# File lib/sequel/database/schema_methods.rb 1069 def unique_constraint_sql_fragment(_) 1070 'UNIQUE' 1071 end
Whether clob should be used for String
text: true columns.
# File lib/sequel/database/schema_methods.rb 1074 def uses_clob_for_text? 1075 false 1076 end
3 - Methods that create datasets
↑ topPublic Instance Methods
Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch
, returning a dataset for arbitrary SQL, with or without placeholders:
DB['SELECT * FROM items'].all DB['SELECT * FROM items WHERE name = ?', my_name].all
Otherwise, acts as an alias for Database#from
, setting the primary table for the dataset:
DB[:items].sql #=> "SELECT * FROM items"
# File lib/sequel/database/dataset.rb 21 def [](*args) 22 args.first.is_a?(String) ? fetch(*args) : from(*args) 23 end
Returns a blank dataset for this database.
DB.dataset # SELECT * DB.dataset.from(:items) # SELECT * FROM items
# File lib/sequel/database/dataset.rb 29 def dataset 30 @dataset_class.new(self) 31 end
Fetches records for an arbitrary SQL statement. If a block is given, it is used to iterate over the records:
DB.fetch('SELECT * FROM items'){|r| p r}
The fetch
method returns a dataset instance:
DB.fetch('SELECT * FROM items').all
fetch
can also perform parameterized queries for protection against SQL injection:
DB.fetch('SELECT * FROM items WHERE name = ?', my_name).all
See caveats listed in Dataset#with_sql regarding datasets using custom SQL and the methods that can be called on them.
# File lib/sequel/database/dataset.rb 49 def fetch(sql, *args, &block) 50 ds = @default_dataset.with_sql(sql, *args) 51 ds.each(&block) if block 52 ds 53 end
Returns a new dataset with the from
method invoked. If a block is given, it acts as a virtual row block
DB.from(:items) # SELECT * FROM items DB.from{schema[:table]} # SELECT * FROM schema.table
# File lib/sequel/database/dataset.rb 60 def from(*args, &block) 61 if block 62 @default_dataset.from(*args, &block) 63 elsif args.length == 1 && (table = args[0]).is_a?(Symbol) 64 @default_dataset.send(:cached_dataset, :"_from_#{table}_ds"){@default_dataset.from(table)} 65 else 66 @default_dataset.from(*args) 67 end 68 end
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1 DB.select{server_version.function} # SELECT server_version() DB.select(:id).from(:items) # SELECT id FROM items
# File lib/sequel/database/dataset.rb 75 def select(*args, &block) 76 @default_dataset.select(*args, &block) 77 end
4 - Methods relating to adapters, connecting, disconnecting, and sharding
↑ topConstants
- ADAPTERS
Array
of supported database adapters
Attributes
Public Class Methods
The Database
subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.
# File lib/sequel/database/connecting.rb 16 def self.adapter_class(scheme) 17 scheme.is_a?(Class) ? scheme : load_adapter(scheme.to_sym) 18 end
Returns the scheme symbol for the Database
class.
# File lib/sequel/database/connecting.rb 21 def self.adapter_scheme 22 @scheme 23 end
Connects to a database. See Sequel.connect.
# File lib/sequel/database/connecting.rb 26 def self.connect(conn_string, opts = OPTS) 27 case conn_string 28 when String 29 if conn_string.start_with?('jdbc:') 30 c = adapter_class(:jdbc) 31 opts = opts.merge(:orig_opts=>opts.dup) 32 opts = {:uri=>conn_string}.merge!(opts) 33 else 34 uri = URI.parse(conn_string) 35 scheme = uri.scheme 36 c = adapter_class(scheme) 37 uri_options = c.send(:uri_to_options, uri) 38 uri.query.split('&').map{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty? 39 uri_options.to_a.each{|k,v| uri_options[k] = URI::DEFAULT_PARSER.unescape(v) if v.is_a?(String)} 40 opts = uri_options.merge(opts).merge!(:orig_opts=>opts.dup, :uri=>conn_string, :adapter=>scheme) 41 end 42 when Hash 43 opts = conn_string.merge(opts) 44 opts = opts.merge(:orig_opts=>opts.dup) 45 c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter']) 46 else 47 raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}" 48 end 49 50 opts = opts.inject({}) do |m, (k,v)| 51 k = :user if k.to_s == 'username' 52 m[k.to_sym] = v 53 m 54 end 55 56 begin 57 db = c.new(opts) 58 if defined?(yield) 59 return yield(db) 60 end 61 ensure 62 if defined?(yield) 63 db.disconnect if db 64 Sequel.synchronize{::Sequel::DATABASES.delete(db)} 65 end 66 end 67 db 68 end
Load the adapter from the file system. Raises Sequel::AdapterNotFound if the adapter cannot be loaded, or if the adapter isn’t registered correctly after being loaded. Options:
- :map
-
The
Hash
in which to look for an already loaded adapter (defaults to ADAPTER_MAP). - :subdir
-
The subdirectory of sequel/adapters to look in, only to be used for loading subadapters.
# File lib/sequel/database/connecting.rb 76 def self.load_adapter(scheme, opts=OPTS) 77 map = opts[:map] || ADAPTER_MAP 78 if subdir = opts[:subdir] 79 file = "#{subdir}/#{scheme}" 80 else 81 file = scheme 82 end 83 84 unless obj = Sequel.synchronize{map[scheme]} 85 # attempt to load the adapter file 86 begin 87 require "sequel/adapters/#{file}" 88 rescue LoadError => e 89 # If subadapter file doesn't exist, just return, 90 # using the main adapter class without database customizations. 91 return if subdir 92 raise Sequel.convert_exception_class(e, AdapterNotFound) 93 end 94 95 # make sure we actually loaded the adapter 96 unless obj = Sequel.synchronize{map[scheme]} 97 raise AdapterNotFound, "Could not load #{file} adapter: adapter class not registered in ADAPTER_MAP" 98 end 99 end 100 101 obj 102 end
Public Instance Methods
Returns the scheme symbol for this instance’s class, which reflects which adapter is being used. In some cases, this can be the same as the database_type
(for native adapters), in others (i.e. adapters with subadapters), it will be different.
Sequel.connect('jdbc:postgres://...').adapter_scheme # => :jdbc
# File lib/sequel/database/connecting.rb 161 def adapter_scheme 162 self.class.adapter_scheme 163 end
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Only usable when using a sharded connection pool.
servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it’s value is overridden with the value provided.
DB.add_servers(f: {host: "hash_host_f"})
# File lib/sequel/database/connecting.rb 173 def add_servers(servers) 174 unless sharded? 175 raise Error, "cannot call Database#add_servers on a Database instance that does not use a sharded connection pool" 176 end 177 178 h = @opts[:servers] 179 Sequel.synchronize{h.merge!(servers)} 180 @pool.add_servers(servers.keys) 181 end
The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database
objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database
objects that are using the same adapter are connecting to different database types.
Sequel.connect('jdbc:postgres://...').database_type # => :postgres
# File lib/sequel/database/connecting.rb 192 def database_type 193 adapter_scheme 194 end
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
- :server
-
Should be a symbol specifing the server to disconnect from,
or an array of symbols to specify multiple servers.
Example:
DB.disconnect # All servers DB.disconnect(server: :server1) # Single server DB.disconnect(server: [:server1, :server2]) # Multiple servers
# File lib/sequel/database/connecting.rb 206 def disconnect(opts = OPTS) 207 pool.disconnect(opts) 208 end
Should only be called by the connection pool code to disconnect a connection. By default, calls the close method on the connection object, since most adapters use that, but should be overwritten on other adapters.
# File lib/sequel/database/connecting.rb 213 def disconnect_connection(conn) 214 conn.close 215 end
Dynamically remove existing servers from the connection pool. Only usable when using a sharded connection pool
servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.
DB.remove_servers(:f1, :f2)
# File lib/sequel/database/connecting.rb 226 def remove_servers(*servers) 227 unless sharded? 228 raise Error, "cannot call Database#remove_servers on a Database instance that does not use a sharded connection pool" 229 end 230 231 h = @opts[:servers] 232 servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}} 233 @pool.remove_servers(servers) 234 end
An array of servers/shards for this Database
object.
DB.servers # Unsharded: => [:default] DB.servers # Sharded: => [:default, :server1, :server2]
# File lib/sequel/database/connecting.rb 240 def servers 241 pool.servers 242 end
Returns true if the database is using a single-threaded connection pool.
# File lib/sequel/database/connecting.rb 245 def single_threaded? 246 @single_threaded 247 end
:nocov:
# File lib/sequel/database/connecting.rb 251 def synchronize(server=nil) 252 @pool.hold(server || :default){|conn| yield conn} 253 end
Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.
# File lib/sequel/database/connecting.rb 277 def test_connection(server=nil) 278 synchronize(server){|conn|} 279 true 280 end
Check whether the given connection is currently valid, by running a query against it. If the query fails, the connection should probably be removed from the connection pool.
# File lib/sequel/database/connecting.rb 286 def valid_connection?(conn) 287 sql = valid_connection_sql 288 begin 289 log_connection_execute(conn, sql) 290 rescue Sequel::DatabaseError, *database_error_classes 291 false 292 else 293 true 294 end 295 end
Private Instance Methods
The default options for the connection pool.
# File lib/sequel/database/connecting.rb 300 def connection_pool_default_options 301 {} 302 end
Return the options for the given server by merging the generic options for all server with the specific options for the given server specified in the :servers option.
# File lib/sequel/database/connecting.rb 307 def server_opts(server) 308 opts = if @opts[:servers] and server_options = @opts[:servers][server] 309 case server_options 310 when Hash 311 @opts.merge(server_options) 312 when Proc 313 @opts.merge(server_options.call(self)) 314 else 315 raise Error, 'Server opts should be a hash or proc' 316 end 317 elsif server.is_a?(Hash) 318 @opts.merge(server) 319 else 320 @opts.dup 321 end 322 opts.delete(:servers) 323 opts 324 end
The SQL query to issue to check if a connection is valid.
# File lib/sequel/database/connecting.rb 327 def valid_connection_sql 328 @valid_connection_sql ||= select(nil).sql 329 end
5 - Methods that set defaults for created datasets
↑ topAttributes
The class to use for creating datasets. Should respond to new with the Database
argument as the first argument, and an optional options hash.
Public Instance Methods
If the database has any dataset modules associated with it, use a subclass of the given class that includes the modules as the dataset class.
# File lib/sequel/database/dataset_defaults.rb 18 def dataset_class=(c) 19 unless @dataset_modules.empty? 20 c = Class.new(c) 21 @dataset_modules.each{|m| c.send(:include, m)} 22 end 23 @dataset_class = c 24 reset_default_dataset 25 end
Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class
as the new dataset_class
, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.
This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database
object uses.
If a block is given, a Dataset::DatasetModule instance is created, allowing for the easy creation of named dataset methods that will do caching.
Examples:
# Introspect columns for all of DB's datasets DB.extend_datasets(Sequel::ColumnsIntrospection) # Trace all SELECT queries by printing the SQL and the full backtrace DB.extend_datasets do def fetch_rows(sql) puts sql puts caller super end end # Add some named dataset methods DB.extend_datasets do order :by_id, :id select :with_id_and_name, :id, :name where :active, :active end DB[:table].active.with_id_and_name.by_id # SELECT id, name FROM table WHERE active ORDER BY id
# File lib/sequel/database/dataset_defaults.rb 62 def extend_datasets(mod=nil, &block) 63 raise(Error, "must provide either mod or block, not both") if mod && block 64 mod = Dataset::DatasetModule.new(&block) if block 65 if @dataset_modules.empty? 66 @dataset_modules = [mod] 67 @dataset_class = Class.new(@dataset_class) 68 else 69 @dataset_modules << mod 70 end 71 @dataset_class.send(:include, mod) 72 reset_default_dataset 73 end
Private Instance Methods
The default dataset class to use for the database
# File lib/sequel/database/dataset_defaults.rb 78 def dataset_class_default 79 Sequel::Dataset 80 end
Whether to quote identifiers by default for this database, true by default.
# File lib/sequel/database/dataset_defaults.rb 89 def quote_identifiers_default 90 true 91 end
Reset the default dataset used by most Database
methods that create datasets.
# File lib/sequel/database/dataset_defaults.rb 83 def reset_default_dataset 84 Sequel.synchronize{@symbol_literal_cache.clear} 85 @default_dataset = dataset 86 end
6 - Methods relating to logging
↑ topAttributes
Whether to include information about the connection in use when logging queries.
Numeric
specifying the duration beyond which queries are logged at warn level instead of info level.
Array
of SQL loggers to use for this database.
Log level at which to log SQL queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level.
Public Instance Methods
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
# File lib/sequel/database/logging.rb 37 def log_connection_yield(sql, conn, args=nil) 38 return yield if skip_logging? 39 sql = "#{connection_info(conn) if conn && log_connection_info}#{sql}#{"; #{args.inspect}" if args}" 40 timer = Sequel.start_timer 41 42 begin 43 yield 44 rescue => e 45 log_exception(e, sql) 46 raise 47 ensure 48 log_duration(Sequel.elapsed_seconds_since(timer), sql) unless e 49 end 50 end
Log a message at error level, with information about the exception.
# File lib/sequel/database/logging.rb 26 def log_exception(exception, message) 27 log_each(:error, "#{exception.class}: #{exception.message.strip if exception.message}: #{message}") 28 end
Log a message at level info to all loggers.
# File lib/sequel/database/logging.rb 31 def log_info(message, args=nil) 32 log_each(:info, args ? "#{message}; #{args.inspect}" : message) 33 end
Remove any existing loggers and just use the given logger:
DB.logger = Logger.new($stdout)
# File lib/sequel/database/logging.rb 55 def logger=(logger) 56 @loggers = Array(logger) 57 end
Private Instance Methods
String
including information about the connection, for use when logging connection info.
# File lib/sequel/database/logging.rb 69 def connection_info(conn) 70 "(conn: #{conn.__id__}) " 71 end
Log the given SQL and then execute it on the connection, used by the transaction code.
# File lib/sequel/database/logging.rb 75 def log_connection_execute(conn, sql) 76 log_connection_yield(sql, conn){conn.public_send(connection_execute_method, sql)} 77 end
Log message with message prefixed by duration at info level, or warn level if duration is greater than log_warn_duration.
# File lib/sequel/database/logging.rb 81 def log_duration(duration, message) 82 log_each((lwd = log_warn_duration and duration >= lwd) ? :warn : sql_log_level, "(#{sprintf('%0.6fs', duration)}) #{message}") 83 end
Log message at level (which should be :error, :warn, or :info) to all loggers.
# File lib/sequel/database/logging.rb 87 def log_each(level, message) 88 @loggers.each{|logger| logger.public_send(level, message)} 89 end
Determine if logging should be skipped. Defaults to true if no loggers have been specified.
# File lib/sequel/database/logging.rb 63 def skip_logging? 64 @loggers.empty? 65 end
7 - Miscellaneous methods
↑ topConstants
- CHECK_CONSTRAINT_SQLSTATES
- DEFAULT_DATABASE_ERROR_REGEXPS
Empty exception regexp to class map, used by default if
Sequel
doesn’t have specific support for the database in use.- DEFAULT_STRING_COLUMN_SIZE
The general default size for string columns for all
Sequel::Database
instances.- EXTENSIONS
Hash
of extension name symbols to callable objects to load the extension into theDatabase
object (usually by extending it with a module defined in the extension).- FOREIGN_KEY_CONSTRAINT_SQLSTATES
- NOT_NULL_CONSTRAINT_SQLSTATES
- SCHEMA_TYPE_CLASSES
Mapping of schema type symbols to class or arrays of classes for that symbol.
- SERIALIZATION_CONSTRAINT_SQLSTATES
- UNIQUE_CONSTRAINT_SQLSTATES
Attributes
The specific default size of string columns for this Sequel::Database
, usually 255 by default.
The options hash for this database
Set the timezone to use for this database, overridding Sequel.database_timezone
.
Public Class Methods
Register a hook that will be run when a new Database
is instantiated. It is called with the new database handle.
# File lib/sequel/database/misc.rb 34 def self.after_initialize(&block) 35 raise Error, "must provide block to after_initialize" unless block 36 Sequel.synchronize do 37 previous = @initialize_hook 38 @initialize_hook = proc do |db| 39 previous.call(db) 40 block.call(db) 41 end 42 end 43 end
Apply an extension to all Database
objects created in the future.
# File lib/sequel/database/misc.rb 46 def self.extension(*extensions) 47 after_initialize{|db| db.extension(*extensions)} 48 end
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
- :before_preconnect
-
Callable that runs after extensions from :preconnect_extensions are loaded, but before any connections are created.
- :cache_schema
-
Whether schema should be cached for this
Database
instance - :default_string_column_size
-
The default size of string columns, 255 by default.
- :extensions
-
Extensions to load into this
Database
instance. Can be a symbol, array of symbols, or string with extensions separated by columns. These extensions are loaded after connections are made by the :preconnect option. - :keep_reference
-
Whether to keep a reference to this instance in Sequel::DATABASES, true by default.
- :logger
-
A specific logger to use.
- :loggers
-
An array of loggers to use.
- :log_connection_info
-
Whether connection information should be logged when logging queries.
- :log_warn_duration
-
The number of elapsed seconds after which queries should be logged at warn level.
- :name
-
A name to use for the
Database
object, displayed in PoolTimeout . - :preconnect
-
Automatically create the maximum number of connections, so that they don’t need to be created as needed. This is useful when connecting takes a long time and you want to avoid possible latency during runtime. Set to :concurrently to create the connections in separate threads. Otherwise they’ll be created sequentially.
- :preconnect_extensions
-
Similar to the :extensions option, but loads the extensions before the connections are made by the :preconnect option.
- :quote_identifiers
-
Whether to quote identifiers.
- :servers
-
A hash specifying a server/shard specific options, keyed by shard symbol .
- :single_threaded
-
Whether to use a single-threaded connection pool.
- :sql_log_level
-
Method to use to log SQL to a logger, :info by default.
All options given are also passed to the connection pool. Additional options respected by the connection pool are :after_connect, :connect_sqls, :max_connections, :pool_timeout, :servers, and :servers_hash. See the connection pool documentation for details.
# File lib/sequel/database/misc.rb 126 def initialize(opts = OPTS) 127 @opts ||= opts 128 @opts = connection_pool_default_options.merge(@opts) 129 @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) 130 @opts[:servers] = {} if @opts[:servers].is_a?(String) 131 @sharded = !!@opts[:servers] 132 @opts[:adapter_class] = self.class 133 @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, Sequel.single_threaded)) 134 @default_string_column_size = @opts[:default_string_column_size] || DEFAULT_STRING_COLUMN_SIZE 135 136 @schemas = {} 137 @prepared_statements = {} 138 @transactions = {} 139 @symbol_literal_cache = {} 140 141 @timezone = nil 142 143 @dataset_class = dataset_class_default 144 @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true)) 145 @dataset_modules = [] 146 @loaded_extensions = [] 147 @schema_type_classes = SCHEMA_TYPE_CLASSES.dup 148 149 self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info 150 self.log_warn_duration = @opts[:log_warn_duration] 151 self.log_connection_info = typecast_value_boolean(@opts[:log_connection_info]) 152 153 @pool = ConnectionPool.get_pool(self, @opts) 154 155 reset_default_dataset 156 adapter_initialize 157 158 keep_reference = typecast_value_boolean(@opts[:keep_reference]) != false 159 begin 160 Sequel.synchronize{::Sequel::DATABASES.push(self)} if keep_reference 161 Sequel::Database.run_after_initialize(self) 162 163 initialize_load_extensions(:preconnect_extensions) 164 165 if before_preconnect = @opts[:before_preconnect] 166 before_preconnect.call(self) 167 end 168 169 if typecast_value_boolean(@opts[:preconnect]) && @pool.respond_to?(:preconnect, true) 170 concurrent = typecast_value_string(@opts[:preconnect]) == "concurrently" 171 @pool.send(:preconnect, concurrent) 172 end 173 174 initialize_load_extensions(:extensions) 175 test_connection if typecast_value_boolean(@opts.fetch(:test, true)) && respond_to?(:connect, true) 176 rescue 177 Sequel.synchronize{::Sequel::DATABASES.delete(self)} if keep_reference 178 raise 179 end 180 end
Register an extension callback for Database
objects. ext should be the extension name symbol, and mod should either be a Module that the database is extended with, or a callable object called with the database object. If mod is not provided, a block can be provided and is treated as the mod object.
# File lib/sequel/database/misc.rb 55 def self.register_extension(ext, mod=nil, &block) 56 if mod 57 raise(Error, "cannot provide both mod and block to Database.register_extension") if block 58 if mod.is_a?(Module) 59 block = proc{|db| db.extend(mod)} 60 else 61 block = mod 62 end 63 end 64 Sequel.synchronize{EXTENSIONS[ext] = block} 65 end
Run the after_initialize
hook for the given instance
.
# File lib/sequel/database/misc.rb 68 def self.run_after_initialize(instance) 69 @initialize_hook.call(instance) 70 end
Private Class Methods
Converts a uri to an options hash. These options are then passed to a newly created database object.
# File lib/sequel/database/misc.rb 74 def self.uri_to_options(uri) 75 { 76 :user => uri.user, 77 :password => uri.password, 78 :port => uri.port, 79 :host => uri.hostname, 80 :database => (m = /\/(.*)/.match(uri.path)) && (m[1]) 81 } 82 end
Public Instance Methods
Cast the given type to a literal type
DB.cast_type_literal(Float) # double precision DB.cast_type_literal(:foo) # foo
# File lib/sequel/database/misc.rb 209 def cast_type_literal(type) 210 type_literal(:type=>type) 211 end
Load an extension into the receiver. In addition to requiring the extension file, this also modifies the database to work with the extension (usually extending it with a module defined in the extension file). If no related extension file exists or the extension does not have specific support for Database
objects, an Error will be raised. Returns self.
# File lib/sequel/database/misc.rb 218 def extension(*exts) 219 Sequel.extension(*exts) 220 exts.each do |ext| 221 if pr = Sequel.synchronize{EXTENSIONS[ext]} 222 if Sequel.synchronize{@loaded_extensions.include?(ext) ? false : (@loaded_extensions << ext)} 223 pr.call(self) 224 end 225 else 226 raise(Error, "Extension #{ext} does not have specific support handling individual databases (try: Sequel.extension #{ext.inspect})") 227 end 228 end 229 self 230 end
Freeze internal data structures for the Database
instance.
# File lib/sequel/database/misc.rb 183 def freeze 184 valid_connection_sql 185 metadata_dataset 186 @opts.freeze 187 @loggers.freeze 188 @pool.freeze 189 @dataset_class.freeze 190 @dataset_modules.freeze 191 @schema_type_classes.freeze 192 @loaded_extensions.freeze 193 metadata_dataset 194 super 195 end
Convert the given timestamp from the application’s timezone, to the databases’s timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 235 def from_application_timestamp(v) 236 Sequel.convert_output_timestamp(v, timezone) 237 end
Returns a string representation of the database object including the class name and connection URI and options used when connecting (if any).
# File lib/sequel/database/misc.rb 241 def inspect 242 a = [] 243 a << uri.inspect if uri 244 if (oo = opts[:orig_opts]) && !oo.empty? 245 a << oo.inspect 246 end 247 "#<#{self.class}: #{a.join(' ')}>" 248 end
Proxy the literal call to the dataset.
DB.literal(1) # 1 DB.literal(:a) # a DB.literal('a') # 'a'
# File lib/sequel/database/misc.rb 255 def literal(v) 256 schema_utility_dataset.literal(v) 257 end
Return the literalized version of the symbol if cached, or nil if it is not cached.
# File lib/sequel/database/misc.rb 261 def literal_symbol(sym) 262 Sequel.synchronize{@symbol_literal_cache[sym]} 263 end
Set the cached value of the literal symbol.
# File lib/sequel/database/misc.rb 266 def literal_symbol_set(sym, lit) 267 Sequel.synchronize{@symbol_literal_cache[sym] = lit} 268 end
Synchronize access to the prepared statements cache.
# File lib/sequel/database/misc.rb 271 def prepared_statement(name) 272 Sequel.synchronize{prepared_statements[name]} 273 end
Proxy the quote_identifier
method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.
# File lib/sequel/database/misc.rb 278 def quote_identifier(v) 279 schema_utility_dataset.quote_identifier(v) 280 end
Return ruby class or array of classes for the given type symbol.
# File lib/sequel/database/misc.rb 283 def schema_type_class(type) 284 @schema_type_classes[type] 285 end
Default serial primary key options, used by the table creation code.
# File lib/sequel/database/misc.rb 288 def serial_primary_key_options 289 {:primary_key => true, :type => Integer, :auto_increment => true} 290 end
Cache the prepared statement object at the given name.
# File lib/sequel/database/misc.rb 293 def set_prepared_statement(name, ps) 294 Sequel.synchronize{prepared_statements[name] = ps} 295 end
Whether this database instance uses multiple servers, either for sharding or for primary/replica configurations.
# File lib/sequel/database/misc.rb 299 def sharded? 300 @sharded 301 end
The timezone to use for this database, defaulting to Sequel.database_timezone
.
# File lib/sequel/database/misc.rb 304 def timezone 305 @timezone || Sequel.database_timezone 306 end
Convert the given timestamp to the application’s timezone, from the databases’s timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 311 def to_application_timestamp(v) 312 Sequel.convert_timestamp(v, timezone) 313 end
Typecast the value to the given column_type. Calls typecast_value_#{column_type} if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.
# File lib/sequel/database/misc.rb 320 def typecast_value(column_type, value) 321 return nil if value.nil? 322 meth = "typecast_value_#{column_type}" 323 begin 324 # Allow calling private methods as per-type typecasting methods are private 325 respond_to?(meth, true) ? send(meth, value) : value 326 rescue ArgumentError, TypeError => e 327 raise Sequel.convert_exception_class(e, InvalidValue) 328 end 329 end
Returns the URI use to connect to the database. If a URI was not used when connecting, returns nil.
# File lib/sequel/database/misc.rb 333 def uri 334 opts[:uri] 335 end
Explicit alias of uri for easier subclassing.
# File lib/sequel/database/misc.rb 338 def url 339 uri 340 end
Private Instance Methods
:nocov:
# File lib/sequel/database/misc.rb 509 def _typecast_value_string_to_decimal(value) 510 d = BigDecimal(value) 511 if d.zero? 512 # BigDecimal parsing is loose by default, returning a 0 value for 513 # invalid input. If a zero value is received, use Float to check 514 # for validity. 515 begin 516 Float(value) 517 rescue ArgumentError 518 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 519 end 520 end 521 d 522 end
Per adapter initialization method, empty by default.
# File lib/sequel/database/misc.rb 345 def adapter_initialize 346 end
Returns true when the object is considered blank. The only objects that are blank are nil, false, strings with all whitespace, and ones that respond true to empty?
# File lib/sequel/database/misc.rb 352 def blank_object?(obj) 353 return obj.blank? if obj.respond_to?(:blank?) 354 case obj 355 when NilClass, FalseClass 356 true 357 when Numeric, TrueClass 358 false 359 when String 360 obj.strip.empty? 361 else 362 obj.respond_to?(:empty?) ? obj.empty? : false 363 end 364 end
Return the Sequel::DatabaseError
subclass to wrap the given exception in.
# File lib/sequel/database/misc.rb 375 def database_error_class(exception, opts) 376 database_specific_error_class(exception, opts) || DatabaseError 377 end
An enumerable yielding pairs of regexps and exception classes, used to match against underlying driver exception messages in order to raise a more specific Sequel::DatabaseError
subclass.
# File lib/sequel/database/misc.rb 369 def database_error_regexps 370 DEFAULT_DATABASE_ERROR_REGEXPS 371 end
Return the SQLState for the given exception, if one can be determined
# File lib/sequel/database/misc.rb 380 def database_exception_sqlstate(exception, opts) 381 nil 382 end
Return a specific Sequel::DatabaseError
exception class if one is appropriate for the underlying exception, or nil if there is no specific exception class.
# File lib/sequel/database/misc.rb 387 def database_specific_error_class(exception, opts) 388 return DatabaseDisconnectError if disconnect_error?(exception, opts) 389 390 if sqlstate = database_exception_sqlstate(exception, opts) 391 if klass = database_specific_error_class_from_sqlstate(sqlstate) 392 return klass 393 end 394 else 395 database_error_regexps.each do |regexp, klss| 396 return klss if exception.message =~ regexp 397 end 398 end 399 400 nil 401 end
Given the SQLState, return the appropriate DatabaseError subclass.
# File lib/sequel/database/misc.rb 409 def database_specific_error_class_from_sqlstate(sqlstate) 410 case sqlstate 411 when *NOT_NULL_CONSTRAINT_SQLSTATES 412 NotNullConstraintViolation 413 when *FOREIGN_KEY_CONSTRAINT_SQLSTATES 414 ForeignKeyConstraintViolation 415 when *UNIQUE_CONSTRAINT_SQLSTATES 416 UniqueConstraintViolation 417 when *CHECK_CONSTRAINT_SQLSTATES 418 CheckConstraintViolation 419 when *SERIALIZATION_CONSTRAINT_SQLSTATES 420 SerializationFailure 421 end 422 end
Return true if exception represents a disconnect error, false otherwise.
# File lib/sequel/database/misc.rb 425 def disconnect_error?(exception, opts) 426 opts[:disconnect] 427 end
Load extensions during initialization from the given key in opts.
# File lib/sequel/database/misc.rb 430 def initialize_load_extensions(key) 431 case exts = @opts[key] 432 when String 433 extension(*exts.split(',').map(&:to_sym)) 434 when Array 435 extension(*exts) 436 when Symbol 437 extension(exts) 438 when nil 439 # nothing 440 else 441 raise Error, "unsupported Database #{key.inspect} option: #{@opts[key].inspect}" 442 end 443 end
Convert the given exception to an appropriate Sequel::DatabaseError
subclass, keeping message and backtrace.
# File lib/sequel/database/misc.rb 447 def raise_error(exception, opts=OPTS) 448 if !opts[:classes] || Array(opts[:classes]).any?{|c| exception.is_a?(c)} 449 raise Sequel.convert_exception_class(exception, database_error_class(exception, opts)) 450 else 451 raise exception 452 end 453 end
Swallow database errors, unless they are connect/disconnect errors.
# File lib/sequel/database/misc.rb 456 def swallow_database_error 457 yield 458 rescue Sequel::DatabaseDisconnectError, DatabaseConnectionError 459 # Always raise disconnect errors 460 raise 461 rescue Sequel::DatabaseError 462 # Don't raise other database errors. 463 nil 464 # else 465 # Don't rescue other exceptions, they will be raised normally. 466 end
Typecast the value to an SQL::Blob
# File lib/sequel/database/misc.rb 469 def typecast_value_blob(value) 470 value.is_a?(Sequel::SQL::Blob) ? value : Sequel::SQL::Blob.new(value) 471 end
Typecast the value to true, false, or nil
# File lib/sequel/database/misc.rb 474 def typecast_value_boolean(value) 475 case value 476 when false, 0, "0", /\Af(alse)?\z/i, /\Ano?\z/i 477 false 478 else 479 blank_object?(value) ? nil : true 480 end 481 end
Typecast the value to a Date
# File lib/sequel/database/misc.rb 484 def typecast_value_date(value) 485 case value 486 when DateTime, Time 487 Date.new(value.year, value.month, value.day) 488 when Date 489 value 490 when String 491 Sequel.string_to_date(value) 492 when Hash 493 Date.new(*[:year, :month, :day].map{|x| (value[x] || value[x.to_s]).to_i}) 494 else 495 raise InvalidValue, "invalid value for Date: #{value.inspect}" 496 end 497 end
Typecast the value to a DateTime or Time depending on Sequel.datetime_class
# File lib/sequel/database/misc.rb 500 def typecast_value_datetime(value) 501 Sequel.typecast_to_application_timestamp(value) 502 end
Typecast the value to a BigDecimal
# File lib/sequel/database/misc.rb 527 def typecast_value_decimal(value) 528 case value 529 when BigDecimal 530 value 531 when Numeric 532 BigDecimal(value.to_s) 533 when String 534 _typecast_value_string_to_decimal(value) 535 else 536 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 537 end 538 end
Typecast the value to an Integer
# File lib/sequel/database/misc.rb 544 def typecast_value_integer(value) 545 (value.is_a?(String) && value =~ /\A0+(\d)/) ? Integer(value, 10) : Integer(value) 546 end
Typecast the value to a String
# File lib/sequel/database/misc.rb 549 def typecast_value_string(value) 550 case value 551 when Hash, Array 552 raise Sequel::InvalidValue, "invalid value for String: #{value.inspect}" 553 else 554 value.to_s 555 end 556 end
Typecast the value to a Time
# File lib/sequel/database/misc.rb 559 def typecast_value_time(value) 560 case value 561 when Time 562 if value.is_a?(SQLTime) 563 value 564 else 565 SQLTime.create(value.hour, value.min, value.sec, value.nsec/1000.0) 566 end 567 when String 568 Sequel.string_to_time(value) 569 when Hash 570 SQLTime.create(*[:hour, :minute, :second].map{|x| (value[x] || value[x.to_s]).to_i}) 571 else 572 raise Sequel::InvalidValue, "invalid value for Time: #{value.inspect}" 573 end 574 end
9 - Methods that describe what the database supports
↑ topPublic Instance Methods
Whether the database uses a global namespace for the index, true by default. If false, the indexes are going to be namespaced per table.
# File lib/sequel/database/features.rb 13 def global_index_namespace? 14 true 15 end
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 19 def supports_create_table_if_not_exists? 20 false 21 end
Whether the database supports deferrable constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 25 def supports_deferrable_constraints? 26 false 27 end
Whether the database supports deferrable foreign key constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 31 def supports_deferrable_foreign_key_constraints? 32 supports_deferrable_constraints? 33 end
Whether the database supports DROP TABLE IF EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 37 def supports_drop_table_if_exists? 38 supports_create_table_if_not_exists? 39 end
Whether the database supports Database#foreign_key_list for parsing foreign keys.
# File lib/sequel/database/features.rb 43 def supports_foreign_key_parsing? 44 respond_to?(:foreign_key_list) 45 end
Whether the database supports Database#indexes for parsing indexes.
# File lib/sequel/database/features.rb 48 def supports_index_parsing? 49 respond_to?(:indexes) 50 end
Whether the database supports partial indexes (indexes on a subset of a table), false by default.
# File lib/sequel/database/features.rb 54 def supports_partial_indexes? 55 false 56 end
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 60 def supports_prepared_transactions? 61 false 62 end
Whether the database and adapter support savepoints, false by default.
# File lib/sequel/database/features.rb 65 def supports_savepoints? 66 false 67 end
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 71 def supports_savepoints_in_prepared_transactions? 72 supports_prepared_transactions? && supports_savepoints? 73 end
Whether the database supports schema parsing via Database#schema
.
# File lib/sequel/database/features.rb 76 def supports_schema_parsing? 77 respond_to?(:schema_parse_table, true) 78 end
Whether the database supports Database#tables for getting list of tables.
# File lib/sequel/database/features.rb 81 def supports_table_listing? 82 respond_to?(:tables) 83 end
Whether the database and adapter support transaction isolation levels, false by default.
# File lib/sequel/database/features.rb 91 def supports_transaction_isolation_levels? 92 false 93 end
Whether DDL statements work correctly in transactions, false by default.
# File lib/sequel/database/features.rb 96 def supports_transactional_ddl? 97 false 98 end
Whether the database supports Database#views for getting list of views.
# File lib/sequel/database/features.rb 86 def supports_view_listing? 87 respond_to?(:views) 88 end
Whether CREATE VIEW … WITH CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 101 def supports_views_with_check_option? 102 !!view_with_check_option_support 103 end
Whether CREATE VIEW … WITH LOCAL CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 106 def supports_views_with_local_check_option? 107 view_with_check_option_support == :local 108 end
Private Instance Methods
Whether the database supports adding primary key constraints on NULLable columns, automatically making them NOT NULL. If false, the columns must be set NOT NULL before the primary key constraint is added.
# File lib/sequel/database/features.rb 115 def can_add_primary_key_constraint_on_nullable_columns? 116 true 117 end
Whether this dataset considers unquoted identifiers as uppercase. True by default as that is the SQL standard
# File lib/sequel/database/features.rb 121 def folds_unquoted_identifiers_to_uppercase? 122 true 123 end
Whether the database supports combining multiple alter table operations into a single query, false by default.
# File lib/sequel/database/features.rb 127 def supports_combining_alter_table_ops? 128 false 129 end
Whether the database supports CREATE OR REPLACE VIEW. If not, support will be emulated by dropping the view first. false by default.
# File lib/sequel/database/features.rb 133 def supports_create_or_replace_view? 134 false 135 end
Whether the database supports named column constraints. True by default. Those that don’t support named column constraints have to have column constraints converted to table constraints if the column constraints have names.
# File lib/sequel/database/features.rb 141 def supports_named_column_constraints? 142 true 143 end
Don’t advertise support for WITH CHECK OPTION by default.
# File lib/sequel/database/features.rb 146 def view_with_check_option_support 147 nil 148 end