28 Feb
2011
28 Feb
'11
2:37 p.m.
Hello all, On Mon, Feb 28, 2011 at 3:31 AM, Larry Garfield <larry@garfieldtech.com> wrote:
Also, subqueries in MySQL are slow only in the WHERE or HAVING clauses, because they run once for each possible record. That is only sometimes a problem in practice. In a FROM clause, however, they're perfectly fine and can be a very good way to "pre filter" a table, as they will only run once.
--Larry Garfield
The reason I ask this because I believe my usage is quite common? Shouldn't someone also need the execute similar queries? Maybe even in the Drupal core I am not aware of. I just wonder if any existing codes can be used. Thanks.