<

运算符说明

< 运算符用于比较运算。当 < 左边运算数值小于 < 右侧运算数值时，< 运算符返回结果为 true。

语法结构

> SELECT x < y;

示例

mysql> SELECT 2 < 2;
+-------+
| 2 < 2 |
+-------+
| false |
+-------+
1 row in set (0.00 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 spID,userID,score from t1 where (userID-1)<spID;
+------+--------+-------+
| spid | userid | score |
+------+--------+-------+
|    1 |      1 |     1 |
|    2 |      2 |     2 |
|    2 |      1 |     4 |
|    3 |      3 |     3 |
|    1 |      1 |     5 |
+------+--------+-------+
5 rows in set (0.00 sec)
mysql> select spID,userID,score from t1 where spID<(userID-1);
+------+--------+-------+
| spid | userid | score |
+------+--------+-------+
|    4 |      6 |    10 |
|    5 |     11 |    99 |
+------+--------+-------+
2 rows in set (0.00 sec)