Question

为什么我在以下SQL语句中出现语法错误：

DECLARE @Count90Day int;

SET @Count90Day =  SELECT COUNT(*) FROM Employee WHERE DateAdd(day,30,StartDate) BETWEEN
DATEADD(day,-10,GETDATE()) AND DATEADD(day,10,GETDATE())  AND Active ='Y'

我正在尝试将从Select语句返回的行数分配给变量@ Count90Day。

Answer 1

子查询周围需要括号：

DECLARE @Count90Day int;

SET @Count90Day =  (SELECT COUNT(*)
                    FROM Employee
                    WHERE DateAdd(day,30,StartDate) BETWEEN DATEADD(day,-10,GETDATE()) AND 
                                                            DATEADD(day,10,GETDATE())  AND
                          Active ='Y'
                   );

您也可以在没有set的情况下将其写为：

DECLARE @Count90Day int;

SELECT @Count90Day =  COUNT(*)
FROM Employee
WHERE DateAdd(day,30,StartDate) BETWEEN DATEADD(day,-10,GETDATE()) AND DATEADD(day,10,GETDATE()) AND
      Active ='Y';

Answer 2

您可以在SELECT内分配，如下所示：

DECLARE @Count90Day int;

SELECT @Count90Day = COUNT(*) 
FROM Employee 
WHERE DateAdd(day,30,StartDate) BETWEEN
DATEADD(day,-10,GETDATE()) AND DATEADD(day,10,GETDATE())  AND Active ='Y'

Answer 3

你不能像SELECT这样分配SQL变量，你可以这样做：

SELECT @Count90Day = COUNT(*) 
FROM Employee WHERE DateAdd(day,30,StartDate) BETWEEN
DATEADD(day,-10,GETDATE()) AND DATEADD(day,10,GETDATE())  AND Active ='Y'

Answer 4

这应该有效

DECLARE @Count90Day int;

SELECT @Count90Day = COUNT(*) FROM Employee WHERE DateAdd(day,30,StartDate) BETWEEN
DATEADD(day,-10,GETDATE()) AND DATEADD(day,10,GETDATE())  AND Active ='Y'

Answer 5

您可以在DECLARE语句中指定变量，只需在请求周围使用圆括号。

DECLARE @Count90Day as int = (SELECT COUNT(*) 
                              FROM Employee 
                              WHERE DateAdd(day,30,StartDate) BETWEEN 
                                    DATEADD(day,-10,GETDATE()) AND
                                    DATEADD(day,10,GETDATE())  
                              AND Active ='Y')

在SQL中从Select语句分配INT变量

5 个答案: