Module: Foreigner::ConnectionAdapters::PostgreSQLAdapter

Includes:
Sql2003
Defined in:
lib/foreigner/connection_adapters/postgresql_adapter.rb

Instance Method Summary collapse

Methods included from Sql2003

#add_foreign_key, #add_foreign_key_sql, #drop_table, #remove_foreign_key, #remove_foreign_key_sql, #supports_foreign_keys?

Instance Method Details

#foreign_keys(table_name) ⇒ Object 



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# File 'lib/foreigner/connection_adapters/postgresql_adapter.rb', line 6

def foreign_keys(table_name)
  fk_info = select_all %{
    SELECT t2.relname AS to_table, a1.attname AS column, a2.attname AS primary_key, c.conname AS name, c.confdeltype AS dependency
    FROM pg_constraint c
    JOIN pg_class t1 ON c.conrelid = t1.oid
    JOIN pg_class t2 ON c.confrelid = t2.oid
    JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
    JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
    JOIN pg_namespace t3 ON c.connamespace = t3.oid
    WHERE c.contype = 'f'
      AND t1.relname = '#{table_name}'
      AND t3.nspname = ANY (current_schemas(false))
    ORDER BY c.conname
  }
  
  fk_info.map do |row|
    options = {:column => row['column'], :name => row['name'], :primary_key => row['primary_key']}

    options[:dependent] = case row['dependency']
      when 'c' then :delete
      when 'n' then :nullify
      when 'r' then :restrict
    end

    ForeignKeyDefinition.new(table_name, row['to_table'], options)
  end
end