module Rein::Constraint::Unique

This module contains methods for defining unique constraints.

Public Instance Methods

add_unique_constraint(*args) click to toggle source
# File lib/rein/constraint/unique.rb, line 9
def add_unique_constraint(*args)
  reversible do |dir|
    dir.up { _add_unique_constraint(*args) }
    dir.down { _remove_unique_constraint(*args) }
  end
end
remove_unique_constraint(*args) click to toggle source
# File lib/rein/constraint/unique.rb, line 16
def remove_unique_constraint(*args)
  reversible do |dir|
    dir.up { _remove_unique_constraint(*args) }
    dir.down { _add_unique_constraint(*args) }
  end
end

Private Instance Methods

_add_unique_constraint(table, attributes, options = {}) click to toggle source
# File lib/rein/constraint/unique.rb, line 25
def _add_unique_constraint(table, attributes, options = {})
  attributes = [attributes].flatten
  name = Util.constraint_name(table, attributes.join('_'), 'unique', options)
  table = Util.wrap_identifier(table)
  attributes = attributes.map { |attribute| Util.wrap_identifier(attribute) }
  initially = options[:deferred] ? 'DEFERRED' : 'IMMEDIATE'
  sql = "ALTER TABLE #{table} ADD CONSTRAINT #{name} UNIQUE (#{attributes.join(', ')})"
  sql << " DEFERRABLE INITIALLY #{initially}" unless options[:deferrable] == false
  execute(sql)
end
_remove_unique_constraint(table, attributes, options = {}) click to toggle source
# File lib/rein/constraint/unique.rb, line 36
def _remove_unique_constraint(table, attributes, options = {})
  attributes = [attributes].flatten
  name = Util.constraint_name(table, attributes.join('_'), 'unique', options)
  table = Util.wrap_identifier(table)
  execute("ALTER TABLE #{table} DROP CONSTRAINT #{name}")
end