如何在mysql中删除列的键约束？

Question

  

如何从Mysql中的列中删除键？（primary，foreign，unique all）

这里我给了列 id

的主键

ALTER TABLE table ADD PRIMARY KEY(id);

现在我想将其删除，并且不使用任何键列 id 是否有任何方式。我用过，

 ALTER TABLE `table` MODIFY `id` INT

但实际上它给出了UNIQUE键

Answer 1

您可以使用

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

Answer 2

您好，您可以运行以下命令：

Alter TABLE tableName MODIFY COLUMN id INT，DROP PRIMARY KEY;

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)