Mysql ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in..的解决方法

昨天在数据库中查看论坛用户的活动时间和访问时间的间隔时，出现ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in..的错误。记录一下。

ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in..的解决方法：

mysql> select lastvisit, lastactivity from pre_common_member_status limit 1;
+------------+--------------+
| lastvisit  | lastactivity |
+------------+--------------+
| 1199200260 |   1198336989 |
+------------+--------------+
1 row in set (0.01 sec)

mysql> select lastvisit-lastactivity from pre_common_member_status limit 1;
+------------------------+
| lastvisit-lastactivity |
+------------------------+
|                 863271 |
+------------------------+
1 row in set (0.05 sec)

mysql> select abs(lastvisit-lastactivity) from pre_common_member_status limit 1;

+-----------------------------+
| abs(lastvisit-lastactivity) |
+-----------------------------+
|                      863271 |
+-----------------------------+
1 row in set (0.03 sec)

mysql> select lastactivity-lastvisit from pre_common_member_status limit 1;
ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in '(`discuz`.`pre_c
ommon_member_status`.`lastactivity` - `discuz`.`pre_common_member_status`.`las
tvisit`)'
mysql> select cast(lastactivity as signed)-cast(lastvisit as signed) from pre_co
mmon_member_status limit 1;
+--------------------------------------------------------+
| cast(lastactivity as signed)-cast(lastvisit as signed) |
+--------------------------------------------------------+
|                                                -863271 |
+--------------------------------------------------------+
1 row in set (0.02 sec)

mysql> select abs(cast(lastactivity as signed)-cast(lastvisit as signed)) from p
re_common_member_status limit 1;
+-------------------------------------------------------------+
| abs(cast(lastactivity as signed)-cast(lastvisit as signed)) |
+-------------------------------------------------------------+
|                                                      863271 |
+-------------------------------------------------------------+
1 row in set (0.00 sec)

mysql>

通过上面的查询我们可以发现，当两个时间戳相减为负数时才会出现ERROR 1690 (22003): BIGINT UNSIGNED value is out of range in..这个错误，但在这个表中两个值中大小不是固定的，lastactivity有可能比lastvisit大，也有可能比lastvisit小。。所以这里可以用cast()来解决。