Question

IF NOT EXISTS (SELECT TOP 1 CityName FROM dbo.City WHERE [Name] = 'Default City')
BEGIN
INSERT dbo.City ( CityName, Status,CityCategoryId) VALUES  
(N'Default City', 0, (SELECT CityCategoryId FROM dbo.CityCategory WHERE [CityCategoryName] = N'Default City Category'))
END
GO

我有上面的查询在SQL Server 2012中正常运行但在SQL Server 2005中失败，并显示以下错误消息。

在此上下文中不允许使用子查询。只允许使用标量表达式。

Answer 1

像这样更改insert。

INSERT dbo.City
       (CityName,Status,CityCategoryId)
SELECT N'Default City',0,CityCategoryId
FROM   dbo.CityCategory
WHERE  [CityCategoryName] = N'Default City Category'

Answer 2

尝试使用变量@CityCategoryId.我不知道@CityCategoryId的类型。您可以使用所需的数据类型。

IF NOT EXISTS (SELECT TOP 1 CityName FROM dbo.City WHERE [Name] = 'Default City')
BEGIN
    Declare @CityCategoryId AS NVARCHAR(100)
    SELECT @CityCategoryId = CityCategoryId FROM dbo.CityCategory 
           WHERE [CityCategoryName] = N'Default City Category'

    INSERT dbo.City( CityName, Status, CityCategoryId) 
    VALUES  
        (N'Default City', 0, @CityCategoryId)
END
GO

Answer 3

试试这样。我不确定......

IF NOT EXISTS (SELECT TOP 1 CityName FROM dbo.City WHERE [Name] = 'Default City')
BEGIN
INSERT dbo.City ( CityName, Status,CityCategoryId)  
SELECT 'Default City',0, CityCategoryId FROM dbo.CityCategory WHERE [CityCategoryName] = N'Default City Category'
END
GO

在SQL插入语句中使用子查询

3 个答案: