Question

我试图设置一个If / Then语句来确定插入＆＃34;课程＆＃34;我的数据库中的表。第一个INSERT INTO将插入限制为6行，第二个将其限制为7。

代码如下所示：

If @courseprogram = 'PharmTech' Then
    INSERT INTO course (fameid, course_id, enroll_status)
    SELECT @fameid fame_id, course_id, 'S' enroll_status FROM calendar
    WHERE startdate >= @startdate AND program = @courseprogram ORDER BY startdate LIMIT 6;
Elseif @fullprogram = 'Medical Assisting'
    INSERT INTO course (fameid, course_id, enroll_status)
    SELECT @fameid fame_id, course_id, 'S' enroll_status FROM calendar
    WHERE startdate >= @startdate AND program = @courseprogram ORDER BY startdate LIMIT 7;
End if

当我尝试运行它时，我收到以下错误消息：

错误代码：1064。您的SQL语法有错误;检查手册，对应右边的MySQL服务器版本语法使用附近＆＃39;如果@courseprogram =＆＃39; PharmTech＆＃39;然后INSERT INTO 当然（fameid，course_id，enr＆＃39; at line 1

有谁知道这里可能出现什么问题？

另外，我已经在这个问题的几篇文章中读过，应该在MySQL中避免使用IF / THEN语句。任何人都可以解释为什么会这样，以及如何处理这个问题？

Answer 1

嗯。嗯。。。这是在单个语句中执行此操作的一种方法：

INSERT INTO course (fameid, course_id, enroll_status)
    (SELECT @fameid as fame_id, course_id, 'S' as enroll_status
     FROM calendar
     WHERE @courseprogram = 'PharmTech' AND
           startdate >= @startdate AND
           program = @courseprogram
     ORDER BY startdate
     LIMIT 6
    ) UNION ALL
    (SELECT @fameid as fame_id, course_id, 'S' as enroll_status
     FROM calendar
     WHERE @fullprogram = 'Medical Assisting' AND
           startdate >= @startdate AND
           program = @courseprogram
     ORDER BY startdate
     LIMIT 7
    );

我并不认为这是优雅。仅仅是它解决了你的问题。

注意：我猜测第二个子查询中的条件@fullprogram = 'Medical Assisting'应该是@courseprogram = 'Medical Assisting'。

MySQL - IF / THEN语句确定INSERT INTO

1 个答案: