=
运算符说明
=
运算符用于比较运算。当 =
左边运算数值等于 =
右侧运算数值时,=
运算符的结果返回 true
。
语法结构
> SELECT x = y;
示例
mysql> SELECT 2 = 2;
+-------+
| 2 = 2 |
+-------+
| true |
+-------+
1 row in set (0.01 sec)
create table t1 (spID smallint,userID bigint,score int);
insert into t1 values (1,1,1);
insert into t1 values (2,2,2);
insert into t1 values (2,1,4);
insert into t1 values (3,3,3);
insert into t1 values (1,1,5);
insert into t1 values (4,6,10);
insert into t1 values (5,11,99);
mysql> select userID,spID,score from t1 where userID=spID and userID=score;
+--------+------+-------+
| userid | spid | score |
+--------+------+-------+
| 1 | 1 | 1 |
| 2 | 2 | 2 |
| 3 | 3 | 3 |
+--------+------+-------+
3 rows in set (0.00 sec)