UNIQUE - 在表中有唯一的行吗？ [英] UNIQUE - way to have unique rows in table?

问题描述

我对数据库表中的唯一行有问题，现在可以这样做：

I have problem with unique rows in db table, now it is posible to do that:

id  | Name  | LastName  | City
-------------------------------------
1   | John  | Moore     | London
2   | John  | Moore     | London

when i use UNIQUE attribute in all columns i have errors inserting second Moore even it is different Name :/

如何使用UNIQUE（或INDEX？）在db中的表格中执行类似操作：

how use UNIQUE (or maybe INDEX?) to do something like that in my table in db:

id  | Name  | LastName  | City
-------------------------------------
1   | John  | Moore     | London
2   | Jake  | Moore     | London
3   | John  | Keen      | London
4   | John  | Moore     | London //but good error when inserting the same row

对不起，如果问题很容易，在sql，并有问题找到一些很好的例子使用UNIQUE像一个想：/
或者也许我必须在插入新行之前从数据库选择一个表，并检查是否存在？

Sorry if question is easy, but i am beginner at sql, and have problems with find some good example with using a UNIQUE like a want:/ or maybe I must just before inserting a new row selecting a table from db and check if it exist?

推荐答案

删除单个列上的唯一索引，并将它们放在两个列上，如下所示：

Remove the unique index on the individual column and make it on both columns together, like this:

CREATE UNIQUE INDEX ixFullName ON yourTable (LastName, Name);

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