module Rein::Constraint::Unique
This module contains methods for defining unique constraints.
Public Instance Methods
add_unique_constraint(*args)
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# 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)
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# 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 = {})
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# 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 = {})
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# 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