ForeignKeySaver

This plugin adds an add_foreign_key_constraint schema method, and extends the schema dump code to output these foreign key constraints.

Only MySQL and PostgreSQL are currently supported.

Examples

adds a constraint on projects.customer_id with parent customers.id

add_foreign_key_constraint :projects, :customer_id, :customers, :id

adds a constraint on projects(a, b) with parent(a, b) with the default RESTRICT update/delete actions

add_foreign_key_constraint "child", ["a", "b"], "parent", ["a", "b"]

adds a constraint with the ON UPDATE action set to CASCADE and the ON DELETE action set to SET NULL

add_foreign_key_constraint 'projects', 'customer_id', 'customers', 'id', :on_update => :cascade, :on_delete => :set_null

The following actions are defined: :restrict :no_action :cascade :set_null (aka :nullify) :set_default Note that MySQL does not support :set_default, and also treats :no_action as :restrict.

Compatibility

Supports mysql, mysql2, postgresql.

Supported Rails 4.1, 4.0, 3.2.13, 3.1.8, 3.0.17, and 2.3.14.