Question

Sql server抱怨这个IF NOT EXISTS语句，说关键字'OR'附近有'错误的语法。

我的查询：

IF NOT EXISTS ( 
                (SELECT * FROM Users where userID = 1)
                OR
                (SELECT * FROM sales WHERE saleID = 1)
              )
BEGIN
            // blah blah blah

END

Answer 1

尝试这种方式而不是

IF 
    NOT EXISTS (SELECT 1 FROM Users where userID = 1)  
AND 
    NOT EXISTS (SELECT 1 FROM sales WHERE saleID = 1)
BEGIN 
       -- blah blah blah
END

或者，如果你坚持分离：

IF NOT (
    EXISTS (SELECT 1 FROM Users where userID = 1)  
    OR 
    EXISTS (SELECT 1 FROM sales WHERE saleID = 1)
)
BEGIN 
    -- blah blah blah
END

EXISTS运算符采用单个select语句并检查任何结果（因此您可以使用常量1而不是*或列名，它更有效）

Answer 2

你想要IF NOT EXISTS（SELECT ...）和NOT EXISTS（SELECT ....）

Answer 3

将“或”改为“工会”

Answer 4

也许这就是你想要做的事情：

IF NOT EXISTS(SELECT * FROM Users WHERE userID = 1) OR (AND) NOT EXISTS(SELECT * FROM sales WHERE saleID = 1)

Sql server抱怨这个IF NOT EXISTS语句

4 个答案: