MYSQL查询速度慢 1W条记录查询需要1个小时间,请问是什么原因。SQL 语句如下。select
CONCAT(rtrim(IFNULL(QuYuFenLei,'')),rtrim(IFNULL(QiShu,'')),rtrim(IFNULL(YuQi,'')),
rtrim(IFNULL(RiQi,'')),rtrim(IFNULL(GongZuoZhouQi,''),
rtrim(IFNULL(SuoZaiZu,''))) onlyid,
DATEDIFF(now(),RiQi) RiQi,
Count(1) HuShu, Sum(GongZuo) JinE from view_weian
group by QuYuFenLei,QiShu,YuQi, RiQi;
CONCAT(rtrim(IFNULL(QuYuFenLei,'')),rtrim(IFNULL(QiShu,'')),rtrim(IFNULL(YuQi,'')),
rtrim(IFNULL(RiQi,'')),rtrim(IFNULL(GongZuoZhouQi,''),
rtrim(IFNULL(SuoZaiZu,''))) onlyid,
DATEDIFF(now(),RiQi) RiQi,
Count(1) HuShu, Sum(GongZuo) JinE from view_weian
group by QuYuFenLei,QiShu,YuQi, RiQi;
CREATE INDEX view_weianI1 ON view_weian(QuYuFenLei,QiShu,YuQi, RiQ);如果view_weian是个大的视图,建议改成存储过程。视图不支持索引,会导致slow query。