SQL 查询中 SELECT 语句中 WITH TIES 关键字的用途是什么?

2021-09-10 00:00:00 tsql sql-server
SELECT TOP 5 WITH TIES EmpNumber,EmpName 
FROM Employee 
Order By EmpNumber DESC

以上查询返回超过五个结果,With Ties"关键字SQL查询有什么用处.

This above query return more than five result, What is the use of "With Ties" keyword SQL Queries.

推荐答案

来自 TOP (Transact-SQL)

当你想返回与最后一个位置并列的两行或更多行时使用在有限的结果集中.

Used when you want to return two or more rows that tie for last place in the limited results set.

注意例子

我们有一张桌子,有 6 个整数,1 到 4 和 5 两次.

We have a table with 6 entires 1 to 4 and 5 twice.

运行

SELECT TOP 5 WITH TIES *
FROM MyTable 
ORDER BY ID;

返回 6 行,因为最后一行是并列的(存在多次.)

returns 6 rows, as the last row is tied (exists more than once.)

在哪里

SELECT TOP 5 WITH TIES *
FROM MyTable 
ORDER BY ID DESC;

只返回 5 行,因为最后一行(在本例中为 2)只存在一次.

returns only 5 rows, as the last row (2 in this case) exists only once.

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