sql - "Incorrect syntax near the keyword ' WHERE '"在 SQL Server 中的 from 子句

Question

SELECT 
   [EmpNum], [EmpEmergencyContact], [Relation], [PhType], [Phone] 
FROM 
    (SELECT 
        [EmpNum], [EmpEmergencyContact], [Relation], [PhType], [Phone] 
    FROM [EMERGENCY_CONTACT])

一个简单的查询，我有一个 SELECT FROM内的声明子句返回错误:

Incorrect syntax near ')'

Answer 1

您需要在 from 语句上放置别名。

所以改变这个:

   FROM [EMERGENCY_CONTACT]
)

对此:

   FROM [EMERGENCY_CONTACT]
) AS tbl

像这样:

SELECT [EmpNum], [EmpEmergencyContact], [Relation], [PhType], [Phone] 
FROM (
    SELECT [EmpNum], [EmpEmergencyContact], [Relation], [PhType], [Phone] 
    FROM [EMERGENCY_CONTACT]
) AS tbl

更安全的是在列上使用别名，如下所示:

SELECT 
    tbl.[EmpNum], 
    tbl.[EmpEmergencyContact], 
    tbl.[Relation], 
    tbl.[PhType], 
    tbl.[Phone] 
FROM (
    SELECT [EmpNum], [EmpEmergencyContact], [Relation], [PhType], [Phone] 
    FROM [EMERGENCY_CONTACT]
) AS tbl