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, #supports_foreign_keys?

Instance Method Details

#foreign_keys(table_name) ⇒ Object 



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# File 'lib/foreigner/connection_adapters/postgresql_adapter.rb', line 16

def foreign_keys(table_name)
  fk_info = select_all %{
    SELECT tc.constraint_name as name
          ,ccu.table_name as to_table
          ,ccu.column_name as primary_key
          ,kcu.column_name as column
          ,rc.delete_rule as dependency
    FROM information_schema.table_constraints tc
    JOIN information_schema.key_column_usage kcu
    USING (constraint_catalog, constraint_schema, constraint_name)
    JOIN information_schema.referential_constraints rc
    USING (constraint_catalog, constraint_schema, constraint_name)
    JOIN information_schema.constraint_column_usage ccu
    USING (constraint_catalog, constraint_schema, constraint_name)
    WHERE tc.constraint_type = 'FOREIGN KEY'
      AND tc.constraint_catalog = '#{@config[:database]}'
      AND tc.table_name = '#{table_name}'
  }
  
  fk_info.map do |row|
    options = {:column => row['column'], :name => row['name'], :primary_key => row['primary_key']}

    if row['dependency'] == 'CASCADE'
      options[:dependent] = :delete
    elsif row['dependency'] == 'SET NULL'
      options[:dependent] = :nullify
    end
    ForeignKeyDefinition.new(table_name, row['to_table'], options)
  end
end

#remove_foreign_key(table, options) ⇒ Object 



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

def remove_foreign_key(table, options)
  if Hash === options
    foreign_key_name = foreign_key_name(table, options[:column], options)
  else
    foreign_key_name = foreign_key_name(table, "#{options.to_s.singularize}_id")
  end

  execute "ALTER TABLE #{quote_table_name(table)} DROP CONSTRAINT #{quote_column_name(foreign_key_name)}"
end