$sql = 'SELECT COUNT(*) ' .
" FROM goods_sku AS gs ".
" LEFT JOIN goods_log AS gl ON gl.sku_id = gs.sku_id
WHERE gl.date>'2011-05-11 14:03:00' AND gs.date>'2011-05-11 14:03:00";
要做这样的查询,以goods_sku为主表, goods_log为从表查询,但是goods_log里的sku_id和goods_sku里的sku_id是多对一的关系,所以这样查询的结果肯定不对(我要的是goods_sku里符合条件的数据,而且取出的结果sku_id不重复),现在这样有重复值,该怎么操作才行?
这种你都可以用子查询来解决select count(*) from
(
SELECT gs.sku_id,gl.sku_id FROM ecs_goods_sku AS gs LEFT JOIN ecs_goods_log AS gl ON gl.sku_id = gs.sku_id GROUP BY gl.sku_id
) tmp
;中间换成其他查询也一样