ITPub博客

首页 > Linux操作系统 > Linux操作系统 > SQL高手篇:精妙SQL语句说明介绍(转)

SQL高手篇:精妙SQL语句说明介绍(转)

原创 Linux操作系统 作者:zaorv 时间:2019-01-07 22:57:05 0 删除 编辑

SQL高手篇:精妙SQL语句说明介绍(转)


  说明:复制表(只复制结构,源表名:a 新表名:b)
  
  SQL: select * into b from a where 1<>1
  
  说明:拷贝表(拷贝数据,源表名:a 目标表名:b)
  
  SQL: insert into b(a, b, c) select d,e,f from b;
  
  说明:显示文章、提交人和最后回复时间
  
  SQL: select a.title,a.username,b.adddate from table a,(select max(adddate)

adddate from table where table.title=a.title) b
  
  说明:外连接查询(表名1:a 表名2:b)
  
  SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c
  
  说明:日程安排提前五分钟提醒
  
  SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5
  
  说明:两张关联表,删除主表中已经在副表中没有的信息
  
  SQL:
  
  delete from info where not exists ( select * from infobz where

info.infid=infobz.infid )
  
  说明:--
  
  SQL:
  
  SELECT A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE FROM TABLE1,(SELECT X.NUM,

X.UPD_DATE, Y.UPD_DATE PREV_UPD_DATE FROM (SELECT NUM, UPD_DATE, INBOUND_QTY,

STOCK_ONHAND FROM TABLE2 WHERE TO_CHAR(UPD_DATE,'YYYY/MM') = TO_CHAR(SYSDATE,

'YYYY/MM')) X, (SELECT NUM, UPD_DATE, STOCK_ONHAND FROM TABLE2 WHERE TO_CHAR

(UPD_DATE,'YYYY/MM') = TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, 'YYYY/MM') ||

'/01','YYYY/MM/DD') - 1, 'YYYY/MM') ) Y, WHERE X.NUM = Y.NUM (+)AND

X.INBOUND_QTY + NVL(Y.STOCK_ONHAND,0) <> X.STOCK_ONHAND ) B WHERE A.NUM = B.NUM
  
  说明:--
  
  SQL:
  
  select * from studentinfo where not exists(select * from student where

studentinfo.id=student.id) and 系名称='"&strdepartmentname&"' and 专业名称

='"&strprofessionname&"' order by 性别,生源地,高考总成绩

  说明: 从数据库中去一年的各单位电话费统计(电话费定额贺电化肥清单两个表来源)
  
  SQL:
  
  SELECT a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') AS

telyear, SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '01', a.factration)) AS JAN,

SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '02', a.factration)) AS FRI, SUM(decode

(TO_CHAR(a.telfeedate, 'mm'), '03', a.factration)) AS MAR, SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '04', a.factration)) AS APR, SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '05', a.factration)) AS MAY, SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '06', a.factration)) AS JUE,SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '07', a.factration)) AS JUL, SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '08', a.factration)) AS AGU, SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '09', a.factration)) AS SEP, SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '10', a.factration)) AS OCT, SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '11', a.factration)) AS NOV,SUM(decode(TO_CHAR

(a.telfeedate, 'mm'), '12', a.factration)) AS DEC FROM (SELECT a.userper, a.tel,

a.standfee, b.telfeedate, b.factration FROM TELFEESTAND a, TELFEE b WHERE a.tel =

b.telfax) a GROUP BY a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy')
  
  说明:四表联查问题:
  
  SQL: select * from a left inner join b on a.a=b.b right inner join c on

a.a=c.c inner join d on a.a=d.d where .....
  
  说明:得到表中最小的未使用的ID号
  SQL:  
  SELECT (CASE WHEN EXISTS(SELECT * FROM Handle b WHERE b.HandleID = 1) THEN

MIN(HandleID) + 1 ELSE 1 END) as HandleID FROM Handle WHERE NOT HandleID IN

(SELECT a.HandleID - 1 FROM Handle a)


来自 “ ITPUB博客 ” ,链接:http://blog.itpub.net/729024/viewspace-564863/,如需转载,请注明出处,否则将追究法律责任。

上一篇: 列转为行
下一篇: 最大的记录
请登录后发表评论 登录
全部评论

注册时间:2018-09-12

  • 博文量
    165
  • 访问量
    121274