Question

我从PowerShell向SQL Server 2005插入行。我需要在我的代码中添加一个WHERE NOT EXISTS子句来停止插入重复项。我正在测试SSMS中的SQL代码，但无法使其工作。

以下代码中的错误在哪里？

INSERT INTO dbo.PrptyValSrce
    (PrptySrceName, PrptyNameSrce, PrptyValSrce, PrptyTS) 
VALUES
    (@property, @propertyDesc, @value, @Timestamp)
WHERE NOT EXISTS
(SELECT * from PrptyValSrce as b
 WHERE b.Seqno
 AND b.PrptySrceName = @property
 AND b.PrptyNameSrce = @propertyDesc
 AND b.PrptyValSrce = @value
 AND b.PrptyTS = @Timestamp);

Answer 1

您的语法无效 - 您无法将WHERE子句应用于VALUES。试试这个：

IF NOT EXISTS(
     SELECT * 
     from PrptyValSrce as b
     WHERE b.Seqno
         AND b.PrptySrceName = @property
         AND b.PrptyNameSrce = @propertyDesc
         AND b.PrptyValSrce = @value
         AND b.PrptyTS = @Timestamp)
    BEGIN
        INSERT INTO dbo.PrptyValSrce
        (PrptySrceName, PrptyNameSrce, PrptyValSrce, PrptyTS) 
        VALUES
        (@property, @propertyDesc, @value, @Timestamp)
    END

Answer 2

您无法执行INSERT....VALUES并为其添加WHERE子句。如果您执行INSERT...VALUES，则会插入这些值 - 句点。

您需要改变检查方式：

IF NOT EXISTS((SELECT * from PrptyValSrce as b
 WHERE b.Seqno
 AND b.PrptySrceName = @property
 AND b.PrptyNameSrce = @propertyDesc
 AND b.PrptyValSrce = @value
 AND b.PrptyTS = @Timestamp)
     INSERT INTO dbo.PrptyValSrce
        (PrptySrceName, PrptyNameSrce, PrptyValSrce, PrptyTS) 
     VALUES
        (@property, @propertyDesc, @value, @Timestamp)

进行IF NOT EXISTS检查，如果成功，那么请INSERT....VALUES。

Answer 3

您也可以

INSERT INTO dbo.PrptyValSrce
    (PrptySrceName, PrptyNameSrce, PrptyValSrce, PrptyTS) 
SELECT @property, @propertyDesc, @value, @Timestamp
WHERE NOT EXISTS
(SELECT * from PrptyValSrce as b
 WHERE b.Seqno
 AND b.PrptySrceName = @property
 AND b.PrptyNameSrce = @propertyDesc
 AND b.PrptyValSrce = @value
 AND b.PrptyTS = @Timestamp);

帮助创建INSERT INTO语句

3 个答案: