SQL Counting Records with Count and Having

问题

I'm having problems with what I thought was a simple query to count records:

SELECT req_ownerid, count(req_status_lender) AS total6 
FROM bor_requests
WHERE (req_status_lender = 0 AND req_status_borrower = 0) OR 
      (req_status_lender = 1 AND req_status_borrower = 1)
GROUP BY req_ownerid 
HAVING req_ownerid = 70

I thought this would count all the records where (req_status_lender = 0 AND req_status_borrower = 0) and (req_status_lender = 1 AND req_status_borrower = 1) and then give me the total but it only gives me the total for either (req_status_lender = 0 AND req_status_borrower = 0) or (req_status_lender = 1 AND req_status_borrower = 1).

Any ideas what I'm doing wrong?

回答1:

You should use the HAVING clause only to limit on something that's been aggregated in your query above - e.g. if you want to select all those rows where a SUM(....) or COUNT(...) is larger than say 5, then you'd use HAVING SUM(...) > 5

What you're doing here is a standard WHERE clause - add it there!

SELECT req_ownerid, count(req_status_lender) AS total6 
FROM bor_requests
WHERE req_ownerid = 70
      AND ((req_status_lender = 0 AND req_status_borrower = 0) OR 
           (req_status_lender = 1 AND req_status_borrower = 1))
GROUP BY req_ownerid 

来源：https://stackoverflow.com/questions/4912792/sql-counting-records-with-count-and-having