Mysql数据库索引的使用

1.索引的使用

查询 表的锁show index from qk_auth_employee

2.走索引

EXPLAIN SELECT * from qk_auth_employee where DataDate = '2018-06-20'

3.走索引

EXPLAIN SELECT * from qk_auth_employee where DataDate <= '2018-06-20' and DataDate > '2018-06-01'

4.不走索引

EXPLAIN SELECT * from qk_auth_employee where DataDate <= '2018-06-20'