So, it violates unique constraint across the collection.

所以，它违背了独特的约束集合。

Can't remove unique constraint since it's the primary key of a table.

唯一约束是表的主键，因此不能移除。

The unique constraint is created in the database when you save the table.

当保存表时，将在数据库中创建该唯一约束。

Tables must have the same primary key, unique index, or unique constraint.

表必须具有相同的主键、唯一索引或唯一约束。

A Unique constraint guarantees that there are no duplicates in a specific column and allows you to define a primary key.

唯一约束可以保证在特定的列中没有重复值并允许您定义一个主键。