SQL Select Query中Top 1 1和Select 1之间的差异 [英] Diff between Top 1 1 and Select 1 in SQL Select Query

问题描述

我对 sql 有一个普遍的疑问.实际上Top 1 1"会做什么?以下查询的含义是什么?

I have a general doubt in sql. What is actually "Top 1 1" will do ? What is the meaning of the below query ?

select top 1 1 from Worker W where not exists (select 1 from Manager M where M.Id = W.Id)

sql server 查询中 select "TOP 1 1" 和 "SELECT 1" 的区别是什么?

what is the diff between select "TOP 1 1" and "SELECT 1" in sql server query ?

推荐答案

SELECT TOP 1 表示选择结果集中的第一条记录

SELECT TOP 1 Means Selecting the very 1st record in the result set

SELECT 1 表示返回1作为结果集

SELECT 1 Means return 1 as the result set

SELECT TOP 1 1 FROM [SomeTable] WHERE <SomeCondition> 表示如果条件为真并且选择返回任何行，则只返回顶部 1 行并且只返回该行的整数 1(没有数据只返回整数 1).

SELECT TOP 1 1 FROM [SomeTable] WHERE <SomeCondition> Means if the condition is true and any rows are returned from the select, only return top 1 row and only return integer 1 for the row (no data just the integer 1 is returned).

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