我来自 MSSQL,现在使用 Mysql,这可能很简单,但是你如何执行一个 如果不存在声明。谢谢
IF NOT EXISTS(SELECT * from users WHERE Username = spUsername)
BEGIN
INSERT into users(ID,Username,Password,Email,Birthdate,DateJoin)
VALUES(UUID(),spUsername,spPassword,spEmail,spBirthDate,NOW());
END
最佳答案
无论如何我都不是数据库专家,但我就是这样做的。
http://www.somethinghitme.com/2010/05/06/mysql-stored-procedures-if-not-exists/
DECLARE SomeId int;
DECLARE CheckExists int;
SET CheckExists = 0;
SELECT 1 INTO CheckExists from lookup_table WHERE someField = in_SomeParam LIMIT 1;
IF (CheckExists > 0) THEN
SELECT id INTO SomeId FROM lookup_table WHERE someField = in_SomeParam;
ELSE
INSERT INTO lookup_table (someField ) VALUES(in_SomeParam);
SELECT SomeId = LAST_INSERT_ID();
END IF;
关于mysql 如果不存在,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7113680/