# **=**

## **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**

```sql
SELECT x = y;
```

## **示例**

```text
mysql> SELECT 2 = 2;
+-------+
| 2 = 2 |
+-------+
| true  |
+-------+
1 row in set (0.01 sec)
```

```text
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)
```