Question

我无法找到语句的语法（或者它是否可能）。

我们正在运行SQL Server 2005，我想做类似的事情：

IF ((SELECT count(*) FROM mytable WHERE userid = 'myid' AND value = 3) < 1) then INSERT INTO mytable VALUES ('myid', 3)

有什么建议吗？感谢

Answer 1

IF ((SELECT count(*) FROM mytable WHERE userid = 'myid' AND value = 3) < 1)
BEGIN
    INSERT INTO mytable VALUES ('myid', 3)
END

IF/ELSE reference

或者您可以使用NOT EXISTS

IF NOT EXISTS (SELECT * FROM mytable WHERE userid = 'myid' AND value = 3)

Answer 2

DECLARE @COUNT int

SET @COUNT=(SELECT count(*) FROM mytable WHERE userid = 'myid' AND value = 3)
IF (@COUNT < 1)
BEGIN
    INSERT INTO mytable VALUES ('myid', 3)
END

Answer 3

您可以尝试在单个语句中执行此操作：

INSERT INTO mytable
SELECT 'myid', 3
WHERE (SELECT count(*) FROM mytable WHERE userid = 'myid' AND value = 3) < 1

我如何/可以在if中运行select SQL语句？

3 个答案: