Class | Sequel::Schema::CreateTableGenerator |
In: |
lib/sequel/database/schema_generator.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 Fixnum Float Numeric BigDecimal Date DateTime Time File TrueClass FalseClass' | Classes specifying generic types that Sequel will convert to database-specific types. |
columns | [R] | Return the column hashes created by this generator |
constraints | [R] | Return the constraint hashes created by this generator |
indexes | [R] | Return the 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.
Do not call this method with untrusted input, as that can result in arbitrary code execution.
# File lib/sequel/database/schema_generator.rb, line 57 57: def self.add_type_method(*types) 58: types.each do |type| 59: class_eval("def #{type}(name, opts={}); column(name, #{type}, opts); end", __FILE__, __LINE__) 60: end 61: 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_eval(&block) if block 41: @columns.unshift(@primary_key) if @primary_key && !has_column?(primary_key_name) 42: end
Add an unnamed constraint to the DDL, 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 68 68: def check(*args, &block) 69: constraint(nil, *args, &block) 70: end
Add a column with the given name, type, and opts to the DDL.
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). If unspecified, will default to whatever the database default is. |
: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 only be used if you have a single, nonautoincrementing primary key column. |
: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 |
# File lib/sequel/database/schema_generator.rb, line 122 122: def column(name, type, opts = OPTS) 123: columns << {:name => name, :type => type}.merge!(opts) 124: if index_opts = opts[:index] 125: index(name, index_opts.is_a?(Hash) ? index_opts : {}) 126: end 127: end
Adds a named constraint (or unnamed if name is nil) to the DDL, 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 137 137: def constraint(name, *args, &block) 138: opts = name.is_a?(Hash) ? name : {:name=>name} 139: constraints << opts.merge(:type=>:check, :check=>block || args) 140: end
Add a foreign key in the table that references another table to the DDL. 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 160 160: def foreign_key(name, table=nil, opts = OPTS) 161: opts = case table 162: when Hash 163: table.merge(opts) 164: when NilClass 165: opts 166: else 167: opts.merge(:table=>table) 168: end 169: return composite_foreign_key(name, opts) if name.is_a?(Array) 170: column(name, Integer, opts) 171: end
Add a full text index on the given columns to the DDL.
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 182 182: def full_text_index(columns, opts = OPTS) 183: index(columns, opts.merge(:type => :full_text)) 184: end
Add an index on the given column(s) with the given options to the DDL. 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 217 217: def index(columns, opts = OPTS) 218: indexes << {:columns => Array(columns)}.merge!(opts) 219: end
Adds an autoincrementing primary key column or a primary key constraint to the DDL. 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, Bigint) primary_key(:id, Bigint, :keep_order=>true) primary_key([:street_number, :house_number], :name=>:some constraint_name)
# File lib/sequel/database/schema_generator.rb, line 255 255: def primary_key(name, *args) 256: return composite_primary_key(name, *args) if name.is_a?(Array) 257: column = @db.serial_primary_key_options.merge({:name => name}) 258: 259: if opts = args.pop 260: opts = {:type => opts} unless opts.is_a?(Hash) 261: if type = args.pop 262: opts = opts.merge(:type => type) 263: end 264: column.merge!(opts) 265: end 266: 267: @primary_key = column 268: if column[:keep_order] 269: columns << column 270: else 271: columns.unshift(column) 272: end 273: end
The name of the primary key for this generator, if it has a primary key.
# File lib/sequel/database/schema_generator.rb, line 276 276: def primary_key_name 277: @primary_key[:name] if @primary_key 278: end
This object responds to all methods.
# File lib/sequel/database/schema_generator.rb, line 228 228: def respond_to_missing?(meth, include_private) 229: true 230: end
Add a unique constraint on the given columns to the DDL.
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 291 291: def unique(columns, opts = OPTS) 292: constraints << {:type => :unique, :columns => Array(columns)}.merge!(opts) 293: end