Module ActiveRecord::ConnectionAdapters::OracleEnhancedSchemaStatementsExt

Adds a new foreign key to the from_table, referencing the primary key of to_table (syntax and partial implementation taken from github.com/matthuhiggins/foreigner)

The foreign key will be named after the from and to tables unless you pass :name as an option.

Examples

Creating a foreign key

add_foreign_key(:comments, :posts)

generates

ALTER TABLE comments ADD CONSTRAINT
   comments_post_id_fk FOREIGN KEY (post_id) REFERENCES posts (id)

Creating a named foreign key

add_foreign_key(:comments, :posts, :name => 'comments_belongs_to_posts')

generates

ALTER TABLE comments ADD CONSTRAINT
   comments_belongs_to_posts FOREIGN KEY (post_id) REFERENCES posts (id)

Creating a cascading foreign_key on a custom column

add_foreign_key(:people, :people, :column => 'best_friend_id', :dependent => :nullify)

generates

ALTER TABLE people ADD CONSTRAINT
   people_best_friend_id_fk FOREIGN KEY (best_friend_id) REFERENCES people (id)
   ON DELETE SET NULL

Supported options

:column

Specify the column name on the from_table that references the to_table. By default this is guessed to be the singular name of the to_table with “_id” suffixed. So a to_table of :posts will use “post_id“ as the default :column.

:primary_key

Specify the column name on the to_table that is referenced by this foreign key. By default this is assumed to be “id”.

:name

Specify the name of the foreign key constraint. This defaults to use from_table and foreign key column.

:dependent

If set to :delete, the associated records in from_table are deleted when records in to_table table are deleted. If set to :nullify, the foreign key column is set to NULL.

# File lib/active_record/connection_adapters/oracle_enhanced_schema_statements_ext.rb, line 68
      def add_foreign_key(from_table, to_table, options = {})
        column = options[:column] || "#{to_table.to_s.singularize}_id"
        constraint_name = foreign_key_constraint_name(from_table, column, options)
        sql = "ALTER TABLE #{quote_table_name(from_table)} ADD CONSTRAINT #{quote_column_name(constraint_name)} "
        sql << foreign_key_definition(to_table, options)
        execute sql
      end

Create primary key trigger (so that you can skip primary key value in INSERT statement). By default trigger name will be “table_name_pkt“, you can override the name with :trigger_name option (but it is not recommended to override it as then this trigger will not be detected by ActiveRecord model and it will still do prefetching of sequence value).

add_primary_key_trigger :users

You can also create primary key trigger using create_table with :primary_key_trigger option:

create_table :users, :primary_key_trigger => true do |t|
  # ...
end

# File lib/active_record/connection_adapters/oracle_enhanced_schema_statements_ext.rb, line 24
      def add_primary_key_trigger(table_name, options)
        # call the same private method that is used for create_table :primary_key_trigger => true
        create_primary_key_trigger(table_name, options)
      end

Add synonym to existing table or view or sequence. Can be used to create local synonym to remote table in other schema or in other database Examples:

add_synonym :posts, "blog.posts"
add_synonym :posts_seq, "blog.posts_seq"
add_synonym :employees, "hr.employees@dblink", :force => true

# File lib/active_record/connection_adapters/oracle_enhanced_schema_statements_ext.rb, line 194
      def add_synonym(name, table_name, options = {})
        sql = "CREATE"
        if options[:force] == true
          sql << " OR REPLACE"
        end
        sql << " SYNONYM #{quote_table_name(name)} FOR #{quote_table_name(table_name)}"
        execute sql
      end

Remove the given foreign key from the table.

Examples

Remove the suppliers_company_id_fk in the suppliers table.

remove_foreign_key :suppliers, :companies

Remove the foreign key named accounts_branch_id_fk in the accounts table.

remove_foreign_key :accounts, :column => :branch_id

Remove the foreign key named party_foreign_key in the accounts table.

remove_foreign_key :accounts, :name => :party_foreign_key

# File lib/active_record/connection_adapters/oracle_enhanced_schema_statements_ext.rb, line 98
      def remove_foreign_key(from_table, options)
        if Hash === options
          constraint_name = foreign_key_constraint_name(from_table, options[:column], options)
        else
          constraint_name = foreign_key_constraint_name(from_table, "#{options.to_s.singularize}_id")
        end
        execute "ALTER TABLE #{quote_table_name(from_table)} DROP CONSTRAINT #{quote_column_name(constraint_name)}"
      end

Remove existing synonym to table or view or sequence Example:

remove_synonym :posts, "blog.posts"

# File lib/active_record/connection_adapters/oracle_enhanced_schema_statements_ext.rb, line 208
      def remove_synonym(name)
        execute "DROP SYNONYM #{quote_table_name(name)}"
      end