Question

如果date_in和date_out都为空，我想更新表roomstatus中的行，其中room_id = @id。否则，我需要插入新行，例如room_id = @ id，date_in = @ dateIn，date_out = @dateIN

IF ((SELECT date_in FROM roomstatus WHERE room_id = @id)= NULL AND (SELECT date_out FROM roomstatus WHERE room_id = @id)= NULL ) THEN 
    UPDATE roomstatus SET date_in = @dateIN, date_out = @dateOut WHERE roomid = @id
ELSE
    INSERT INTO roomstatus (room_id,date_in,date_out) VALUES (@id,@dateIn,@dateOut)
END IF;

MySQL说：

> #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use
> near 'IF ((SELECT date_in FROM roomstatus WHERE room_id = @id)= NULL
> AND (SELECT date_' at line 1

Answer 1

您的程序有些错误 1）每个语句都需要一个终止符2）MYSQL无法将列名与参数名区分开，例如WHERE room_id = roomID-（mysql会将列与其自身进行比较），您必须提供该信息3）关闭开始的结尾需要具有结束定界符。以下在语法上是正确的

DROP PROCEDURE IF EXISTS P;

DELIMITER // 
CREATE PROCEDURE P(IN INdateIn DATETIME(6) , IN INdateOut DATETIME(6), IN INroomID INT(11)) 
BEGIN 
    IF EXISTS (SELECT room_id FROM roomstatus WHERE room_id = INroomID AND date_in = NULL AND date_out = NULL ) THEN
     UPDATE roomstatus 
        SET date_in = INdateIn , date_out = INdateOut 
         WHERE room_id = INroomID ;
    ELSE 
        INSERT INTO roomstatus (room_id,date_in,date_out) VALUES (INroomID,INdateIn,INdateOut); 
    END IF;
END //
DELIMITER ;

从功能上我不太确定，没有错误检查以确保您已设置参数来实现想要的操作。例如，您没有测试indateout，因此代码可能会输入将indateout设置为null并将indatein设置为有效值的更新逻辑-下次调用该过程时，您可能会输入插入逻辑并可能以重复项结尾。 / p>

IF附近无法识别的语句-使用IF存在

1 个答案: