运用union和in哪一个效率高【MySQL教程】,union,效率高,哪个

一直都认为是in的效力要高，然则此次确有点蒙圈。

SELECT * FROM runinfo WHERE status in (0,2,1,3,4,7,9,10);

这个查询的效力是，经常是1秒多。

mysql> SELECT * FROM runinfo WHERE status in (0,2,1,3,4,7,9,10);

106 rows in set (1.20 sec)

替换成下面这类写法以后，

SELECT * FROM runinfo WHERE status = 0
union
SELECT * FROM runinfo WHERE status = 1
union
SELECT * FROM runinfo WHERE status = 2
union
SELECT * FROM runinfo WHERE status = 3
union
SELECT * FROM runinfo WHERE status = 4
union
SELECT * FROM runinfo WHERE status = 7
union
SELECT * FROM runinfo WHERE status = 9
union
SELECT * FROM runinfo WHERE status = 10

效力有很大的提拔。