Question

我测试了SQL的每个部分，它运行正常。

我的WHERE条款有些错误但是......在VS 2012中没有详细设置断点但是......

这应该是使用MS SQL SERVER的子查询的INSERT语句的代码吗？

INSERT INTO Emails (email, insertDate) 
VALUES (@Email, @DateToday) 
WHERE NOT EXISTS (SELECT Emails.email 
                  FROM Emails WHERE Emails.email = @Email);

Answer 1

INSERT INTO Emails (email, insertDate) 
SELECT @Email, @DateToday
WHERE NOT EXISTS (SELECT Emails.email 
                  FROM Emails WHERE Emails.email = @Email);

Answer 2

这将有效

INSERT INTO Emails (email, insertDate) 
SELECT @Email, @DateToday
WHERE NOT EXISTS (SELECT Emails.email 
                  FROM Emails WHERE Emails.email = @Email)

但更好的解决方案可能是电子邮件列中的唯一索引

Answer 3

尝试使用以下内容：

"INSERT INTO Emails (email, insertDate) VALUES ('@Email', '@DateToday') WHERE NOT EXISTS (SELECT Emails.email FROM Emails WHERE Emails.email = '@Email');"

Answer 4

INSERT INTO Emails (email, insertDate) 
SELECT Email, DateToday
WHERE NOT EXISTS (SELECT Emails.email 
                  FROM Emails WHERE Emails.email = Email)

它会将email设置为非空列或唯一索引。

如何正确编码INSERT子查询？

4 个答案: