I have a query to the effect of
SELECT t3.id, a,bunch,of,other,stuff FROM t1, t2, t3
WHERE (associate t1,t2, and t3 with each other)
GROUP BY t3.id
LIMIT 10,20
I want to know to many total rows this query would return without the LIMIT (so I can show pagination information).
Normally, I would use this query:
SELECT COUNT(t3.id) FROM t1, t2, t3
WHERE (associate t1,t2, and t3 with each other)
GROUP BY t3.id
However the GROUP BY changes the meaning of the COUNT, and instead I get a set of rows representing the number of unique t3.id values in each group.
Is there a way to get a count for the total number of rows when I use a GROUP BY? I'd like to avoid having to execute the entire query and just counting the number of rows, since I only need a subset of the rows because the values are paginated. I'm using MySQL 5, but I think this pretty generic.
Best Answer
There is a nice solution in MySQL.
Add the keyword SQL_CALC_FOUND_ROWS right after the keyword SELECT :
After that, run another query with the function FOUND_ROWS() :
It should return the number of rows without the LIMIT clause.
Checkout this page for more information : http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_found-rows