Class | Sequel::Schema::CreateTableGenerator |
In: |
lib/sequel/database/schema_generator.rb
lib/sequel/extensions/schema_dumper.rb |
Parent: | Object |
Schema::CreateTableGenerator is an internal class that the user is not expected to instantiate directly. Instances are created by Database#create_table. It is used to specify table creation parameters. It takes a Database object and a block of column/index/constraint specifications, and gives the Database a table description, which the database uses to create a table.
Schema::CreateTableGenerator has some methods but also includes method_missing, allowing users to specify column type as a method instead of using the column method, which makes for a nicer DSL.
For more information on Sequel‘s support for schema modification, see the "Schema Modification" guide.
GENERIC_TYPES | = | %w'String Integer Float Numeric BigDecimal Date DateTime Time File TrueClass FalseClass'.freeze | Classes specifying generic types that Sequel will convert to database-specific types. |
columns | [R] | Column hashes created by this generator |
constraints | [R] | Constraint hashes created by this generator |
indexes | [R] | Index hashes created by this generator |
Add a method for each of the given types that creates a column with that type as a constant. Types given should either already be constants/classes or a capitalized string/symbol with the same name as a constant/class.
# File lib/sequel/database/schema_generator.rb, line 60 60: def self.add_type_method(*types) 61: types.each do |type| 62: case type 63: when Symbol, String 64: method = type 65: type = Object.const_get(type) 66: else 67: method = type.to_s 68: end 69: 70: define_method(method){|name, opts=OPTS| column(name, type, opts)} 71: end 72: nil 73: end
Set the database in which to create the table, and evaluate the block in the context of this object.
# File lib/sequel/database/schema_generator.rb, line 34 34: def initialize(db, &block) 35: @db = db 36: @columns = [] 37: @indexes = [] 38: @constraints = [] 39: @primary_key = nil 40: instance_exec(&block) if block 41: @columns.unshift(@primary_key) if @primary_key && !has_column?(primary_key_name) 42: end
Add an unnamed constraint, specified by the given block or args:
check(num: 1..5) # CHECK num >= 1 AND num <= 5 check{num > 5} # CHECK num > 5
# File lib/sequel/database/schema_generator.rb, line 80 80: def check(*args, &block) 81: constraint(nil, *args, &block) 82: end
Add a column with the given name, type, and opts #
column :num, :integer # num INTEGER column :name, String, null: false, default: 'a' # name varchar(255) NOT NULL DEFAULT 'a' inet :ip # ip inet
You can also create columns via method missing, so the following are equivalent:
column :number, :integer integer :number
The following options are supported:
:collate : | The collation to use for the column. For backwards compatibility, only symbols and string values are supported, and they are used verbatim. However, on PostgreSQL, symbols are literalized as regular identifiers, since unquoted collations are unlikely to be valid. |
:default : | The default value for the column. |
:deferrable : | For foreign key columns, this ensures referential integrity will work even if referencing table uses a foreign key value that does not yet exist on referenced table (but will exist before the transaction commits). Basically it adds DEFERRABLE INITIALLY DEFERRED on key creation. If you use :immediate as the value, uses DEFERRABLE INITIALLY IMMEDIATE. |
:index : | Create an index on this column. If given a hash, use the hash as the options for the index. |
:key : | For foreign key columns, the column in the associated table that this column references. Unnecessary if this column references the primary key of the associated table, except if you are using MySQL. |
:null : | Mark the column as allowing NULL values (if true), or not allowing NULL values (if false). The default is to allow NULL values. |
:on_delete : | Specify the behavior of this column when being deleted (:restrict, :cascade, :set_null, :set_default, :no_action). |
:on_update : | Specify the behavior of this column when being updated (:restrict, :cascade, :set_null, :set_default, :no_action). |
:primary_key : | Make the column as a single primary key column. This should not be used if you have a single, nonautoincrementing primary key column (use the primary_key method in that case). |
:primary_key_constraint_name : | The name to give the primary key constraint |
:type : | Overrides the type given as the argument. Generally not used by column itself, but can be passed as an option to other methods that call column. |
:unique : | Mark the column as unique, generally has the same effect as creating a unique index on the column. |
:unique_constraint_name : | The name to give the unique key constraint |
MySQL specific options:
:generated_always_as : | Specify a GENERATED ALWAYS AS column expression, if generated columns are supported. |
:generated_type : | Set the type of column when using :generated_always_as, should be :virtual or :stored to force a type. |
# File lib/sequel/database/schema_generator.rb, line 139 139: def column(name, type, opts = OPTS) 140: columns << {:name => name, :type => type}.merge!(opts) 141: if index_opts = opts[:index] 142: index(name, index_opts.is_a?(Hash) ? index_opts : OPTS) 143: end 144: nil 145: end
Adds a named constraint (or unnamed if name is nil), with the given block or args. To provide options for the constraint, pass a hash as the first argument.
constraint(:blah, num: 1..5) # CONSTRAINT blah CHECK num >= 1 AND num <= 5 constraint({name: :blah, deferrable: true}, num: 1..5) # CONSTRAINT blah CHECK num >= 1 AND num <= 5 DEFERRABLE INITIALLY DEFERRED
# File lib/sequel/database/schema_generator.rb, line 155 155: def constraint(name, *args, &block) 156: opts = name.is_a?(Hash) ? name : {:name=>name} 157: constraints << opts.merge(:type=>:check, :check=>block || args) 158: nil 159: end
Dump this generator‘s columns to a string that could be evaled inside another instance to represent the same columns
# File lib/sequel/extensions/schema_dumper.rb, line 393 393: def dump_columns 394: strings = [] 395: cols = columns.dup 396: cols.each do |x| 397: x.delete(:on_delete) if x[:on_delete] == :no_action 398: x.delete(:on_update) if x[:on_update] == :no_action 399: end 400: if (pkn = primary_key_name) && !@primary_key[:keep_order] 401: cols.delete_if{|x| x[:name] == pkn} 402: pk = @primary_key.dup 403: pkname = pk.delete(:name) 404: @db.serial_primary_key_options.each{|k,v| pk.delete(k) if v == pk[k]} 405: strings << "primary_key #{pkname.inspect}#{opts_inspect(pk)}" 406: end 407: cols.each do |c| 408: c = c.dup 409: name = c.delete(:name) 410: strings << if table = c.delete(:table) 411: c.delete(:type) if c[:type] == Integer || c[:type] == 'integer' 412: "foreign_key #{name.inspect}, #{table.inspect}#{opts_inspect(c)}" 413: elsif pkn == name 414: @db.serial_primary_key_options.each{|k,v| c.delete(k) if v == c[k]} 415: "primary_key #{name.inspect}#{opts_inspect(c)}" 416: else 417: type = c.delete(:type) 418: opts = opts_inspect(c) 419: case type 420: when Class 421: "#{type.name} #{name.inspect}#{opts}" 422: when :Bignum 423: "Bignum #{name.inspect}#{opts}" 424: else 425: "column #{name.inspect}, #{type.inspect}#{opts}" 426: end 427: end 428: end 429: strings.join("\n") 430: end
Dump this generator‘s constraints to a string that could be evaled inside another instance to represent the same constraints
# File lib/sequel/extensions/schema_dumper.rb, line 434 434: def dump_constraints 435: cs = constraints.map do |c| 436: c = c.dup 437: type = c.delete(:type) 438: case type 439: when :check 440: raise(Error, "can't dump check/constraint specified with Proc") if c[:check].is_a?(Proc) 441: name = c.delete(:name) 442: if !name and c[:check].length == 1 and c[:check].first.is_a?(Hash) 443: "check #{c[:check].first.inspect[1...-1]}" 444: else 445: "#{name ? "constraint #{name.inspect}," : 'check'} #{c[:check].map(&:inspect).join(', ')}" 446: end 447: when :foreign_key 448: c.delete(:on_delete) if c[:on_delete] == :no_action 449: c.delete(:on_update) if c[:on_update] == :no_action 450: c.delete(:deferrable) unless c[:deferrable] 451: cols = c.delete(:columns) 452: table = c.delete(:table) 453: "#{type} #{cols.inspect}, #{table.inspect}#{opts_inspect(c)}" 454: else 455: cols = c.delete(:columns) 456: "#{type} #{cols.inspect}#{opts_inspect(c)}" 457: end 458: end 459: cs.join("\n") 460: end
Dump this generator‘s indexes to a string that could be evaled inside another instance to represent the same indexes. Options:
:add_index : | Use add_index instead of index, so the methods can be called outside of a generator but inside a migration. The value of this option should be the table name to use. |
:drop_index : | Same as add_index, but create drop_index statements. |
:ignore_errors : | Add the ignore_errors option to the outputted indexes |
# File lib/sequel/extensions/schema_dumper.rb, line 469 469: def dump_indexes(options=OPTS) 470: is = indexes.map do |c| 471: c = c.dup 472: cols = c.delete(:columns) 473: if table = options[:add_index] || options[:drop_index] 474: "#{options[:drop_index] ? 'drop' : 'add'}_index #{table.inspect}, #{cols.inspect}#{', :ignore_errors=>true' if options[:ignore_errors]}#{opts_inspect(c)}" 475: else 476: "index #{cols.inspect}#{opts_inspect(c)}" 477: end 478: end 479: is = is.reverse if options[:drop_index] 480: is.join("\n") 481: end
Add a foreign key in the table that references another table. See column for available options.
foreign_key(:artist_id) # artist_id INTEGER foreign_key(:artist_id, :artists) # artist_id INTEGER REFERENCES artists foreign_key(:artist_id, :artists, key: :id) # artist_id INTEGER REFERENCES artists(id) foreign_key(:artist_id, :artists, type: String) # artist_id varchar(255) REFERENCES artists(id)
Additional Options:
:foreign_key_constraint_name : | The name to give the foreign key constraint |
If you want a foreign key constraint without adding a column (usually because it is a composite foreign key), you can provide an array of columns as the first argument, and you can provide the :name option to name the constraint:
foreign_key([:artist_name, :artist_location], :artists, name: :artist_fk) # ADD CONSTRAINT artist_fk FOREIGN KEY (artist_name, artist_location) REFERENCES artists
# File lib/sequel/database/schema_generator.rb, line 179 179: def foreign_key(name, table=nil, opts = OPTS) 180: opts = case table 181: when Hash 182: table.merge(opts) 183: when NilClass 184: opts 185: else 186: opts.merge(:table=>table) 187: end 188: return composite_foreign_key(name, opts) if name.is_a?(Array) 189: column(name, Integer, opts) 190: end
Add a full text index on the given columns.
PostgreSQL specific options:
:index_type : | Can be set to :gist to use a GIST index instead of the default GIN index. |
:language : | Set a language to use for the index (default: simple). |
Microsoft SQL Server specific options:
:key_index : | The KEY INDEX to use for the full text index. |
# File lib/sequel/database/schema_generator.rb, line 201 201: def full_text_index(columns, opts = OPTS) 202: index(columns, opts.merge(:type => :full_text)) 203: end
Add an index on the given column(s) with the given options. General options:
:name : | The name to use for the index. If not given, a default name based on the table and columns is used. |
:type : | The type of index to use (only supported by some databases) |
:unique : | Make the index unique, so duplicate values are not allowed. |
:where : | Create a partial index (only supported by some databases) |
PostgreSQL specific options:
:concurrently : | Create the index concurrently, so it doesn‘t block operations on the table while the index is being built. |
:opclass : | Use a specific operator class in the index. |
Microsoft SQL Server specific options:
:include : | Include additional column values in the index, without actually indexing on those values. |
index :name # CREATE INDEX table_name_index ON table (name) index [:artist_id, :name] # CREATE INDEX table_artist_id_name_index ON table (artist_id, name)
# File lib/sequel/database/schema_generator.rb, line 236 236: def index(columns, opts = OPTS) 237: indexes << {:columns => Array(columns)}.merge!(opts) 238: nil 239: end
Adds an autoincrementing primary key column or a primary key constraint. To just create a constraint, the first argument should be an array of column symbols specifying the primary key columns. To create an autoincrementing primary key column, a single symbol can be used. In both cases, an options hash can be used as the second argument.
If you want to create a primary key column that is not autoincrementing, you should not use this method. Instead, you should use the regular column method with a primary_key: true option.
If an array of column symbols is used, you can specify the :name option to name the constraint.
Options:
:keep_order : | For non-composite primary keys, respects the existing order of columns, overriding the default behavior of making the primary key the first column. |
Examples:
primary_key(:id) primary_key(:id, type: :Bignum, keep_order: true) primary_key([:street_number, :house_number], name: :some constraint_name)
# File lib/sequel/database/schema_generator.rb, line 274 274: def primary_key(name, *args) 275: return composite_primary_key(name, *args) if name.is_a?(Array) 276: column = @db.serial_primary_key_options.merge({:name => name}) 277: 278: if opts = args.pop 279: opts = {:type => opts} unless opts.is_a?(Hash) 280: if type = args.pop 281: opts = opts.merge(:type => type) 282: end 283: column.merge!(opts) 284: end 285: 286: @primary_key = column 287: if column[:keep_order] 288: columns << column 289: else 290: columns.unshift(column) 291: end 292: nil 293: end
The name of the primary key for this generator, if it has a primary key.
# File lib/sequel/database/schema_generator.rb, line 296 296: def primary_key_name 297: @primary_key[:name] if @primary_key 298: end
This object responds to all methods.
# File lib/sequel/database/schema_generator.rb, line 248 248: def respond_to_missing?(meth, include_private) 249: true 250: end
Add a unique constraint on the given columns.
unique(:name) # UNIQUE (name)
Supports the same :deferrable option as column. The :name option can be used to name the constraint.
# File lib/sequel/database/schema_generator.rb, line 311 311: def unique(columns, opts = OPTS) 312: constraints << {:type => :unique, :columns => Array(columns)}.merge!(opts) 313: nil 314: end