sql脚本练习01

原来在聚鲨的练习题（实际操作）(已经理解了)

left join ,inner join , right join 的区别

主要需要理解的部分是：inner join 乐翻天join right join 的区别。二者之间的区别是以谁为主要的表，主要显示谁的问题。

表连接的方式

其次需要理解的是 select * from a inner join b on a.khdm = b.khdm inner join c on c.khdm = a.khdm 只要是可以继续下去的就可以 不断的写下去

加入一个固定的值的方式

第三个需要注意的是：我的可以在我想加入的渠道中显示任何我已经有的知识。如“北京” tb

select *
  from (select distinct a.KHDM, a.zfl
          from hqods.yg_res_ddyjb a
         -- left join hqods.yg_ref_good_info b
           -- on a.spbh = b.spbh
         where a.zfl in ('纪念收藏品')
         and a.khdj in ('紫金会员', '黄金会员', '普通会员','白金会员', '钻石会员')
         --group by khdm, b.zfl
         ) m
  inner join (select CUST_ID khdm, CUST_LVL_DESC 会员等级, province_nm
               from hqods.yg_dim_customer h
              where CUST_LVL_DESC in ('紫金会员',
                                      '黄金会员',
                                      '普通会员',
                                      '白金会员',
                                      '钻石会员')) x
    on x.khdm = m.khdm
  inner join (select e.customernumber,
                            u.name,
                            g.grpname,
                            e.bindstatus,
                            '北京' TB
                       from hqods.v_bf_crm_cp_customer e ---------------会员明细，绑定关系
                      inner join hqods.crm_sys_user u
                         on e.assignedusr = u.usrid
                      inner join hqods.crm_sys_uglink ug
                         on ug.usrid = u.usrid
                      inner join hqods.crm_sys_grp g
                         on g.grpid = ug.grpid
                      inner join (select g.grpid,
                                        g.grpname,
                                        g.parentid,
                                        rownum rn
                                   from hqods.crm_sys_grp g
                                  where g.type = '1'
                                  start with g.grpid = 'mgrLv'
                                 connect by prior g.grpid = g.parentid) t1
                         on g.grpid = t1.grpid
                      inner join (select g.grpid,
                                        g.grpname,
                                        g.parentid,
                                        rownum rn
                                   from hqods.crm_sys_grp g
                                  where g.type = '1'
                                  start with g.grpid = 'AGENTGRP'
                                 connect by prior g.grpid = g.parentid) t
                         on g.grpid = t.grpid
                      where e.bindstatus = 1) h
               --left join (select grpname 组, td from hqods.v_yg_dim_dsjzb) e
                -- on h.grpname = e.组
             -- group by customernumber, name, grpname, td
            --  ) f
    on m.khdm = h.customernumber