[not] between and 不在/在什么范围之内 [not] in () 列在不在某个范围之内 is [not] null 是否为空 //案例 //[not] between and 不在/在什么范围之内 mysql> select 5 between 1 and 10; //1在不在1~10之间 +--------------------+ | 5 between 1 and 10 | +--------------------+ | 1 | //1表示肯定，0表示否定 +--------------------+ 1 row in set (0.37 sec) mysql> select 50 between 1 and 10; +---------------------+ | 50 between 1 and 10 | +---------------------+ | 0 | +---------------------+ 1 row in set (0.00 sec) //[not] in () 列在不在某个范围之内 mysql> select 50 in (1,25,50,75); +--------------------+ | 50 in (1,25,50,75) | +--------------------+ | 1 | +--------------------+ 1 row in set (0.01 sec) //is [not] null 是否为空 mysql> select * from test where name is null; //is null +------+------+ | name | age | +------+------+ | NULL | 2 | +------+------+ 1 row in set (0.00 sec) mysql> select * from test where name is not null; //name is not null +----------+------+ | name | age | +----------+------+ | xiaodeng | 29 | | erzi | 1 | | | NULL | +----------+------+ 3 rows in set (0.00 sec)