如何在MYSQL中设置列的最大值？

Question

我有一个名为WORKERS的表，该表由totalNumberOfWorkers组成，我想将worker的最大值设置为30，并且不应超过30，它的范围应在0到30之间。 / p>

我已经尝试过了，但是它不起作用并显示错误，我的代码不正确。

ALTER TABLE WORKERS
CONSTRAINT WORKERS_CHECK CHECK (totalNumberOfWorkers => 0 AND totalNumberOfWorkers <31);

以下是称为“工作人员”的表

+------------------------+-------------+------+-----+---------+-------+
| Field                  | Type        | Null | Key | Default | Extra |
+------------------------+-------------+------+-----+---------+-------+
| WorkerID               | int(6)      | NO   | PRI | NULL    |       |
| dateOfWork             | date        | NO   |     | NULL    |       |
| timeOfWork             | time        | NO   |     | NULL    |       |
| descOfWorker           | varchar(50) | NO   |     | NULL    |       |
| totalNumberOfWorkers   | int(2)      | NO   |     | NULL    |       |
+------------------------+-------------+------+-----+---------+-------+

Answer 1

找到了解决方案

ALTER TABLE WORKERS
ADD CONSTRAINT TOTALNUMBER_CHECK1 CHECK(totalNumberOfWorkers BETWEEN 1 AND 30);