如何删除mysql中列的键约束？

Question

如何从Mysql的列中移除键？(主键、外键、唯一键)

这里，我给出了列id的主键

ALTER TABLE table ADD PRIMARY KEY(id);

现在我想删除它，并使无键列id是有任何方法的。

 ALTER TABLE `table` MODIFY `id` INT

但实际上它给出了唯一的钥匙

Answer 1

您可以使用

 ALTER TABLE `table` MODIFY `id` INT ;
 ALTER TABLE `table` DROP PRIMARY KEY;

Answer 2

嗨，您可以运行以下命令：

更改表tableName修改列id INT，删除主键；

​

mysql> desc TestTable;

+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(10)     | NO   | PRI | NULL    |       |
| name  | varchar(30) | NO   |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.05 sec)

mysql> ALTER TABLE TestTable MODIFY COLUMN id INT(10),DROP PRIMARY KEY;
Query OK, 0 rows affected (0.62 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> desc TestTable;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id    | int(10)     | YES  |     | NULL    |       |
| name  | varchar(30) | NO   |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.00 sec)

​