SQL Server 三个表及以上的关联查询
三表关联查询
select u.user_id,u.user_name,u.user_sex,c.college_name,s.subject_name,s.achievement
from user u
LEFT JOIN subject s ON s.user_number=u. user_id
LEFT JOIN college c ON c.subject_number=s.subject_id;
。
。
。
可继续添加
三表关联查询
select u.user_id,u.user_name,u.user_sex,c.college_name,s.subject_name,s.achievement
from user u
LEFT JOIN subject s ON s.user_number=u. user_id
LEFT JOIN college c ON c.subject_number=s.subject_id;
。
。
。
可继续添加