存储过程 求大佬

[一小只123]

CREATE DEFINER=`root`@`%` PROCEDURE `dddddddd`(in collegeId VARCHAR(20),majorId VARCHAR(20),classId VARCHAR(20),type VARCHAR(20),startTime  VARCHAR(50),endTime  VARCHAR(50),pageSize int(10),pageNum int(10))
begin
set @sql=null;
select GROUP_CONCAT(DISTINCT CONCAT('sum(case p.name',' when ''',p.name,''' then t.user_score else 0 end) as ''',p.name,''''))  into @sql  
from account_student as s
left join (select a.user_score,a.user_id,a.paper_id from exam_paper_user_record as a ,(select user_id ,paper_id,max(add_time) as maxtime 
from exam_paper_user_record   group by user_id, paper_id)as  b, exam_paper as p  WHERE a.user_id=b.user_id AND a.paper_id=b.paper_id and  p.paper_id=b.paper_id  AND a.add_time = b.maxtime and p.type=type and s.college_Id=collegeId)
as t on t.user_id=s.user_id left join exam_paper as p on p.paper_id=t.paper_id where p.type=type;

type,collegeId可能是null 怎么让他是空的时候去掉这个查询条件 要哭了 mysql

简易版
select name into username from users where id=userId and user_name=userName;
userId, userName为传入值为空的话怎么去掉这个条件

[一小只123]

顶一下

[percentfl]

多加上一个判断就可以
将id=userId 变更为 (id=userId or userId is null)
userName同理

[牛光敏]

select name into username from users where id=nvl(userId,id) and user_name=nvl(userName,user_name)

[一小只123]

感谢 收下我的膝盖