SQL Server中的嵌套选择语句 [英] Nested select statement in SQL Server
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问题描述
为什么以下各项不起作用?
Why doesn't the following work?
SELECT name FROM (SELECT name FROM agentinformation)
我想我对SQL的理解是错误的，因为我本以为这会返回与
I guess my understanding of SQL is wrong, because I would have thought this would return the same thing as
SELECT name FROM agentinformation
内部select语句是否不创建外部SELECT语句然后查询的结果集?
Doesn't the inner select statement create a result set which the outer SELECT statement then queries?
推荐答案
您需要为子查询添加别名.
You need to alias the subquery.
SELECT name FROM (SELECT name FROM agentinformation) a
或更明确地说
SELECT a.name FROM (SELECT name FROM agentinformation) a
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