关于oracle使用到的函数整理

1.Oracle中REGEXP_SUBSTR函数：

在oracle中某字段数值为用逗号（,）隔开的值，如图所示

现在需要将这条数据拆分成两条数据，其它字段显示值不变都一样，

select cc.*,
       tt.name tname,
       tt.encrypt_telphone,
       tt.encrypt_name,
       tt.encrypt_address
  from (select c.*, REGEXP_SUBSTR(c.task_id, '[^,]+', 1, l) AS taskid
          from ep_crm_customer_shlgxx c,
               (SELECT LEVEL l FROM DUAL CONNECT BY LEVEL <= 30)
         WHERE l <= LENGTH(c.task_id) - LENGTH(REPLACE(c.task_id, ',')) + 1) cc
  left join ep_crm_task tt
    on cc.task_id = tt.id
 where 1 = 1
   and cc.assign = 1
   and cc.agent_id = '10001'
 order by cc.assign_time desc, cc.id desc

得到结果

页面显示：

2.Oracle中lead over, lag over 函数：

获取数据的上一条或下一条数据，根据某字段order by

select n.next_cust_id
                 from (select cw.id,
                              lead(cw.id, 1, 0) over(order by cw.assign_time desc, cw.id desc) as next_cust_id,
                              t.name tname,
                              cw.name,
                              cw.telephone,
                              cw.mobile,
                              cw.coment,
                              cw.intent,
                              cw.create_time,
                              cw.dial_time
                         from ep_crm_customer_shlgxx cw
                         left join ep_crm_task t
                           on cw.task_id = t.id
                        where 1 = 1
                          and cw.assign = 1
                          and cw.agent_id = '10001') n
                where n.id = 'ee27acf7-83c0-45bc-924c-a624915b18c2'

执行结果如下图所示：