oracle-sql计算

1.计算当前时间最近的15分整点数据

    select rdc.city_code          as city_id,
           rdc.city_name,
           rdc.DIS_FAIL_ORDER_NUM as RES_PREE_FAILURE_NUM,
           --以下是计算最近的整分时间
           to_char(sysdate, 'hh24') || ':' ||
           CASE trunc(to_char(sysdate, 'mi') / 15, 0)
             WHEN 0 THEN
              '00'
             WHEN 1 THEN
              '15'
             WHEN 2 THEN
              '30'
             WHEN 3 THEN
              '45'
             ELSE
              '00'
           END as HOUR_MIN
      from res_dis_city rdc
     where rdc.create_date =
           (select max(t.create_date) from res_dis_city t);

2.根据地市递归计算地市底下的所有区县

and ba.area_id in (SELECT b.area_id                    
                               FROM bfm_area b                    
                              START WITH b.area_id = :areaId      
                             CONNECT BY PRIOR area_id = parent_id)

3.根据某个字段相同，其他字段排序 获取第N行数据

select *
  from (select (case
                 when ua.grade in ('C3', 'C4') then
                  (select area_name from uos_area where area_id = ua.parent_id)
                 else
                  ua.area_name
               end) as pAreaName,
               ua.area_name as areaName,
               (select gridname from res_dd_grid where gridid = uo.grid_id) as gridName,
               us.staff_name as staffName,
               us.mobile_tel as mobileTel,
               (select unit_name from res_dd_grid where gridid = uo.grid_id) as unitName,
               decode(pst.traning_status, 0, '未完成', '完成') as traningName,
               decode(pst.exam_pass, 0, '未考试', 1, '通过', '未通过') as examPassName,
               us.staff_id,
               uo.org_tmp_id,
               uj.job_id,
               row_number() over(partition by us.staff_id order by uo.org_tmp_id desc, uj.job_id asc) as row_no
          from t_people_traning_score pst,
               uos_staff              us,
               uos_job_staff          ujs,
               uos_job                uj,
               uos_job_priv           ujp,
               uos_role               ur,
               uos_org                uo,
               uos_area               ua
         where pst.traning_id = 513 --这个修改成实际值
           and us.staff_id = pst.staff_id
           and ujs.staff_id = us.staff_id
           and uj.job_id = ujs.job_id
           and ujp.job_id = uj.job_id
           and ur.role_id = ujp.role_id
           and ur.role_name in ('网格长', '社区经理') --这个修改成灵活配置的那种SQL
           and uo.org_id = uj.org_id
           and ua.area_id = uo.area_id)
 where row_no = 1;

4. 获取某个月的最后一天

select * from rpt_chn_index5 where day_id=to_number(to_char(last_day(to_date('201704','yyyymm')),'yyyymmdd'));

5.获取当前第一条数据

where rownum = 1

如果前面的数据先按照时间字段排序了。再用where rownum = 1 可以得出当前最新的数据

6.统计地市+底下所有区县的总数

select count(*) as taoToal,
                    (case ba.grade
                      when 'C3' then
                       ba.area_id
                      when 'C4' then
                       ba.parent_id
                    end) as groupAreaId
               from TINF_ALARM_ORDER tao
               LEFT JOIN bfm_area ba
                 on tao.area_id = ba.area_id
              where 1 = 1
        and tao.Fault_Type = 'MFS'
              group by (case ba.grade
                         when 'C3' then
                          ba.area_id
                         when 'C4' then
                          ba.parent_id
                       end)

7.高效删除重复记录的方法

DELETE FROM EMP E
WHERE E.ROWID > (SELECT MIN(X.ROWID)
FROM EMP X
WHERE X.EMP_NO = E.EMP_NO
)