同时使用 DISTINCT 和 TOP

Using DISTINCT and TOP at the same time(同时使用 DISTINCT 和 TOP)

问题描述

我想使用不同的 &在同一时间，我做到了

I want to use distinct & top in the same time , i did

SELECT distinct TOP 10 * FROM TableA

但我仍然有一个重复的 PersonId 所以我很难做到:

but i still have a duplicate PersonId so i tought to do :

SELECT distinct (personID) TOP 10 * FROM TableA但是语法错误，所以我想知道是否有任何解决方案

SELECT distinct (personID) TOP 10 * FROM TableA but the syntax is wrong , so i wonder if there is any solution

谢谢，

推荐答案

您正在使用一个 SELECT * 来提取所有记录.如果你想使用真正的 DISTINCT 只列出你想要接收不同值的列.如果您有多个列，那么所有这些列组合起来构成一个不同的记录.

You're using a SELECT * which is pulling in all records. If you want to use a true DISTINCT only list out the column you want to receive distinct values of. If you have multiple columns then all those columns combined make up one distinct record.

SELECT distinct TOP 10 personID 
FROM TableA

请注意，如果没有 ORDER BY，这将返回没有特定顺序的前 10 条记录.每次运行查询时结果可能不同.

Note that without an ORDER BY this will return the first 10 records in no particular order. The results could be different each time you run the query.

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