如何为从 SELECT 语句创建的临时表定义键?
我有:
CREATE temporary TABLE _temp_unique_parts_trading 
engine=memory AS 
  (SELECT parts_trading.enquiryref, 
          sellingcurrency, 
          jobs.id AS jobID 
   FROM   parts_trading, 
          jobs 
   WHERE  jobs.enquiryref = parts_trading.enquiryref 
   GROUP  BY parts_trading.enquiryref) 
但是我在哪里定义键?