带连接的嵌套查询

Question

如何检索我想用连接编写嵌套查询的数据？ 我想在first_name中显示designation，t1，并在project_name col2; t2，end_date= (select max(end_date) from project where res_id=?) p>

你能帮我写一下sql查询吗

select R.first_name, R.Designation, R.DOB, R.DOJ, R.Department, 
R.city, p.project_name, p.start_date, p.end_date, 
p.end_date+1 as next_avail_date 
from resources R full JOIN project p on (r.res_id=p.res_id) 
where r.u_id='&u_id';

我想根据以下查询选择项目名称

select project_name from project where end_date= (select max(end_date) from project where res_id=1);

如何在上述查询中添加它？

Answer 1

您可以使用子查询作为FROM CLAUSE的视图，并以与表相同的方式连接它。尝试使用类似的东西

select R.first_name, 
       R.Designation, 
       R.DOB, R.DOJ, 
       R.Department, 
       R.city,     
       p.project_name, 
       p.start_date, 
       p.end_date, 
       p.end_date+1 as next_avail_date 
  from resources r, (select project_name 
                       from project 
                      where end_date= (select max(end_date) 
                                         from project pr 
                                        where pr.res_id=1)) p
 where r.u_id='&u_id'
   and r.res_id=p.res_id;