Question

How do I define the keys for a temporary table that is being created from a SELECT statement?

I have:

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) 

But where do I define the keys?

Answer 1

You can do this

CREATE temporary TABLE _temp_unique_parts_trading 
(
  enquiryref varchar(255),
  sellingcurrency varchar(255),
  jobID int(10),
  key(jobId)
)
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) 

Basically append the table schema (index, column data type) right after TABLE_NAME