Question

要求我编写一个存储过程，该过程将创建（插入）调查响应，以SurveyGUID为输入，而SurveyResponseGUID为输出。但是，当我插入响应后设置输出时，我返回null。

执行插入时，是否可以设置OUT参数？

插入有效，当我删除INTO零件时，设置输出参数的查询也可以独立工作。我试图找到解决方案，但我并不幸运。我是MySQL的新手，所以将不胜感激任何帮助或技巧。


USE db;
DROP PROCEDURE IF EXISTS spCreateSurveyResponse;
DELIMITER ??

CREATE PROCEDURE spCreateSurveyResponse(
    IN surveyGUID varchar(36),
    OUT responseGUID varchar(36))
BEGIN 
    SET @surveyId = ( SELECT SurveyId FROM db.Survey WHERE SurveyGuid = surveyGUID);

    INSERT INTO SurveyResponse (SurveyId, ResponseGuid) VALUES (@surveyId, UUID());

    SELECT 
        ResponseGuid INTO responseGUID
        FROM 
            db.SurveyResponse 
        WHERE 
            SurveyDetailId = last_insert_id();

END ??


DELIMITER ;

-- CALL spCreateSurveyResponse('Survey GUID here', @responseGUID);
-- SELECT @responseGUID;

当我从另一个SQL文件中调用过程时，SELECT @responseGUID始终返回Null。

Answer 1

根据Jitendra的评论，我尝试更改参数的名称，并且成功了！

USE db;
DROP PROCEDURE IF EXISTS spCreateSurveyResponse;
DELIMITER ??

CREATE PROCEDURE spCreateSurveyResponse(
    IN param_surveyGUID varchar(36),
    OUT param_responseGUID varchar(36))
BEGIN 
    SET @surveyId = ( SELECT SurveyId FROM db.Survey WHERE SurveyGuid = param_surveyGUID);

    INSERT INTO SurveyResponse (SurveyId, ResponseGuid) VALUES (@surveyId, UUID());

    SELECT 
        ResponseGuid INTO param_responseGUID
        FROM 
            db.SurveyResponse 
        WHERE 
            SurveyDetailId = last_insert_id();

END ??

存储过程输出返回空值

1 个答案: