Re: Efficient way to count rows when using GROUP BY
| From: | Micah Stevens | Date: | Sun, 26 Jun 2005 16:10:09 +0000 |
| Subject: | Re: Efficient way to count rows when using GROUP BY | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-39772@lists.php.net to get a copy of this message | ||
If you don't want a group count, but want a total row count instead, there's
no reason to have the group by statement, If you're trying to have a
conglomerate result, where one column is always equal to the total count,
wouldn't it be more efficient to have a seperate query for that?
-Micah
> Hi All,
>
> I use
>
> SELECT COUNT(*) FROM whatever WHERE whatever
>
> to determine how many rows a particular query will return (then use this
> count to assist with pagination).
>
> The problem is that this does not work if the query contains a GROUP BY
> statement as, of course, the query will return many rows each with a count
> by each grouping.
>
> Does anyone know an efficient way to determine the number of ROWS a query
> with a GROUP BY statement will return (without just executing the entire
> query with no LIMIT statement)?
>
> Thanks ... Ross