SQL Server 2005 对两列的唯一约束
如何在 SQL Server 2005 中为两列添加唯一约束?所以可以说我有:
How do you add a unique constraint in SQL Server 2005 to two columns? So lets say that I have:
PK, A, B ...
x1 1 1
x2 1 2
x3 2 1
x4 2 2
我不应该添加另一行x5"并且 A 和 B 的值是 1,1,因为它们已经在 x1 的数据库中?
I should not be able to add another row 'x5' and have the values for A and B be 1,1 as they are already in the database in x1?
好的,我们设法让它工作,感谢 OMG.转到表视图,选择两列,右键单击并选择索引/键"-常规选项卡,选择要唯一的列,然后将唯一"设置为true.这是使用表设计器.
Ok we managed to get it to work and thanks to OMG. Go to the table view, select the two columns, right click and select 'indexes/keys' - general tab, select the columns you want to be unique and then set 'is unique' to true. This is using the table designer.
谢谢.
在 SQL Server 中,唯一约束实际上是作为唯一索引实现的.使用:
In SQL Server, a unique constraint is really implemented as a unique index. Use:
CREATE UNIQUE INDEX <uix_name> ON <table_name>(<col_A>, <col_B>)
有关详细信息,请参阅此 MSDN 页面一>.
For more info, see this MSDN page.