I have a table with primary key auto_increment and I am having a duplicate data problem. To solve this I tried to create a composite primary key but it's not possible: #1068 - Multiple primary key defined.
我有一个主键auto_increment的表,我有一个重复的数据问题。为了解决这个问题,我试图创建一个复合主键,但这是不可能的:#1068 - 定义了多个主键。
I can't drop the primary key because there are relationship with other tables and I can't just put Unique constraint in only one column because the rule is to be composite.
我不能删除主键,因为与其他表有关系,我不能只将Unique约束放在一列中,因为规则是复合的。
What can I do? I am using MySQL.
我能做什么?我正在使用MySQL。
1 个解决方案
#1
Modifying the primary key on a table is a tricky exercise. This is doubly true when the existing key is defined auto-increment.
修改表上的主键是一项棘手的练习。当现有密钥定义为自动增量时,这是双重的。
You can create a composite unique key, though.
但是,您可以创建复合唯一键。
ALTER TABLE ADD UNIQUE KEY (`column1`, `column2');
#1
Modifying the primary key on a table is a tricky exercise. This is doubly true when the existing key is defined auto-increment.
修改表上的主键是一项棘手的练习。当现有密钥定义为自动增量时,这是双重的。
You can create a composite unique key, though.
但是,您可以创建复合唯一键。
ALTER TABLE ADD UNIQUE KEY (`column1`, `column2');