# File lib/active_record/connection_adapters/mysql2_adapter.rb, line 508 def pk_and_sequence_for(table) keys = [] result = execute("describe #{quote_table_name(table)}") result.each(:symbolize_keys => true, :as => :hash) do |row| keys << row[:Field] if row[:Key] == "PRI" end keys.length == 1 ? [keys.first, nil] : nil end