oracle 多表联接join

1，Equijoins:主键和外键

SQL> select t1.ku_id,t1.ku_lid,t2.ku_id,t2.kr_id
  2  from wk_t_user t1,wk_t_userole t2
  3  where t1.ku_id=t2.ku_id;

     KU_ID KU_LID                    KU_ID      KR_ID
---------- -------------------- ---------- ----------
         1 guest                         1          2
         2 superman                      2          2
         2 superman                      2          3
         2 superman                      2         13
        11 admin                        11         12
        11 admin                        11         13

2，Non-Equijoins:非等值联接

3，Outer joins:分为左联接和右联接

  右联接：

SQL> select t1.ku_id,t1.ku_lid,t2.ku_id,t2.kr_id
  2  from wk_t_user t1,wk_t_userole t2
  3  where t1.ku_id(+)=t2.ku_id;

     KU_ID KU_LID                    KU_ID      KR_ID
---------- -------------------- ---------- ----------
         1 guest                         1          2
         2 superman                      2         13
         2 superman                      2          3
         2 superman                      2          2

4，左联接：

SQL> select t1.ku_id,t1.ku_lid,t2.ku_id,t2.kr_id
  2  from wk_t_user t1,wk_t_userole t2
  3  where t1.ku_id=t2.ku_id(+);

     KU_ID KU_LID                    KU_ID      KR_ID
---------- -------------------- ---------- ----------
         1 guest                         1          2
         2 superman                      2          2
         2 superman                      2          3
         2 superman                      2         13
        11 admin                        11         12
        11 admin                        11         13
        12 info                         12         13

5，Self Joins;

  如：select worker.last_name,manager.last_name from employees worker,employees manager where worker.manager_id=manager.employee_id

6，join .. on..

 如：select t1.stor_id,t1.stor_name,t2.stor_id from stores t1 join sales t2

on t1.stor_id=t2.stor_id;