Class: Sequel::Schema::AlterTableGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/sequel/database/schema_generator.rb

Overview

Schema::AlterTableGenerator is an internal class that the user is not expected to instantiate directly. Instances are created by Database#alter_table. It is used to specify table alteration parameters. It takes a Database object and a block of operations to perform on the table, and gives the Database a table an array of operations, which the database uses to alter a table’s description.

For more information on Sequel’s support for schema modification, see the “Migrations and Schema Modification” guide.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db, &block) ⇒ AlterTableGenerator

Set the Database object to which to apply the DDL, and evaluate the block in the context of this object.



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# File 'lib/sequel/database/schema_generator.rb', line 219

def initialize(db, &block)
  @db = db
  @operations = []
  instance_eval(&block) if block
end

Instance Attribute Details

#operations ⇒ Object (readonly)

An array of DDL operations to perform



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# File 'lib/sequel/database/schema_generator.rb', line 215

def operations
  @operations
end

Instance Method Details

#add_column(name, type, opts = {}) ⇒ Object

Add a column with the given name, type, and opts to the DDL for the table. See Generator#column for the available options.



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# File 'lib/sequel/database/schema_generator.rb', line 227

def add_column(name, type, opts = {})
  @operations << {:op => :add_column, :name => name, :type => type}.merge(opts)
end

#add_constraint(name, *args, &block) ⇒ Object

Add a constraint with the given name and args to the DDL for the table. See Generator#constraint.



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# File 'lib/sequel/database/schema_generator.rb', line 233

def add_constraint(name, *args, &block)
  @operations << {:op => :add_constraint, :name => name, :type => :check, :check => block || args}
end

#add_foreign_key(name, table, opts = {}) ⇒ Object

Add a foreign key with the given name and referencing the given table to the DDL for the table. See Generator#column for the available options.

You can also pass an array of column names for creating composite foreign keys. In this case, it will assume the columns exists and will only add the constraint.

NOTE: If you need to add a foreign key constraint to an existing column use the composite key syntax even if it is only one column.



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# File 'lib/sequel/database/schema_generator.rb', line 251

def add_foreign_key(name, table, opts = {})
  return add_composite_foreign_key(name, table, opts) if name.is_a?(Array)
  add_column(name, Integer, {:table=>table}.merge(opts))
end

#add_full_text_index(columns, opts = {}) ⇒ Object

Add a full text index on the given columns to the DDL for the table. See Generator#index for available options.



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# File 'lib/sequel/database/schema_generator.rb', line 258

def add_full_text_index(columns, opts = {})
  add_index(columns, {:type=>:full_text}.merge(opts))
end

#add_index(columns, opts = {}) ⇒ Object

Add an index on the given columns to the DDL for the table. See Generator#index for available options.



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# File 'lib/sequel/database/schema_generator.rb', line 264

def add_index(columns, opts = {})
  @operations << {:op => :add_index, :columns => Array(columns)}.merge(opts)
end

#add_primary_key(name, opts = {}) ⇒ Object

Add a primary key to the DDL for the table. See Generator#column for the available options.



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# File 'lib/sequel/database/schema_generator.rb', line 270

def add_primary_key(name, opts = {})
  return add_composite_primary_key(name, opts) if name.is_a?(Array)
  opts = @db.serial_primary_key_options.merge(opts)
  add_column(name, opts.delete(:type), opts)
end

#add_spatial_index(columns, opts = {}) ⇒ Object

Add a spatial index on the given columns to the DDL for the table. See Generator#index for available options.



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# File 'lib/sequel/database/schema_generator.rb', line 278

def add_spatial_index(columns, opts = {})
  add_index(columns, {:type=>:spatial}.merge(opts))
end

#add_unique_constraint(columns, opts = {}) ⇒ Object

Add a unique constraint to the given column(s)



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# File 'lib/sequel/database/schema_generator.rb', line 238

def add_unique_constraint(columns, opts = {})
  @operations << {:op => :add_constraint, :type => :unique, :columns => Array(columns)}.merge(opts)
end

#drop_column(name) ⇒ Object

Remove a column from the DDL for the table.



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# File 'lib/sequel/database/schema_generator.rb', line 283

def drop_column(name)
  @operations << {:op => :drop_column, :name => name}
end

#drop_constraint(name) ⇒ Object

Remove a constraint from the DDL for the table.



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# File 'lib/sequel/database/schema_generator.rb', line 288

def drop_constraint(name)
  @operations << {:op => :drop_constraint, :name => name}
end

#drop_index(columns, options = {}) ⇒ Object

Remove an index from the DDL for the table.



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# File 'lib/sequel/database/schema_generator.rb', line 293

def drop_index(columns, options={})
  @operations << {:op => :drop_index, :columns => Array(columns)}.merge(options)
end

#rename_column(name, new_name, opts = {}) ⇒ Object

Modify a column’s name in the DDL for the table.



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# File 'lib/sequel/database/schema_generator.rb', line 298

def rename_column(name, new_name, opts = {})
  @operations << {:op => :rename_column, :name => name, :new_name => new_name}.merge(opts)
end

#set_column_allow_null(name, allow_null) ⇒ Object

Modify a column’s NOT NULL constraint.



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# File 'lib/sequel/database/schema_generator.rb', line 313

def set_column_allow_null(name, allow_null)
  @operations << {:op => :set_column_null, :name => name, :null => allow_null}
end

#set_column_default(name, default) ⇒ Object

Modify a column’s default value in the DDL for the table.



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# File 'lib/sequel/database/schema_generator.rb', line 303

def set_column_default(name, default)
  @operations << {:op => :set_column_default, :name => name, :default => default}
end

#set_column_type(name, type, opts = {}) ⇒ Object

Modify a column’s type in the DDL for the table.



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# File 'lib/sequel/database/schema_generator.rb', line 308

def set_column_type(name, type, opts={})
  @operations << {:op => :set_column_type, :name => name, :type => type}.merge(opts)
end