本站首页    管理页面    写新日志    退出


«August 2025»
12
3456789
10111213141516
17181920212223
24252627282930
31


公告
 本博客在此声明所有文章均为转摘,只做资料收集使用。

我的分类(专题)

日志更新

最新评论

留言板

链接

Blog信息
blog名称:
日志总数:1304
评论数量:2242
留言数量:5
访问次数:7583200
建立时间:2006年5月29日




[MySQL]SQL 精妙语句 
软件技术,  电脑与网络

lhwork 发表于 2006/7/11 10:06:20

如何从一位菜鸟蜕变成为高手,灵活使用的SQL语句是必不可少的。本文收集了部分比较经典,常用的SQL语句供大家参考,希望对大家有所帮助。   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') &brvbar;&brvbar; '/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)


阅读全文(1818) | 回复(0) | 编辑 | 精华
 



发表评论:
昵称:
密码:
主页:
标题:
验证码:  (不区分大小写,请仔细填写,输错需重写评论内容!)



站点首页 | 联系我们 | 博客注册 | 博客登陆

Sponsored By W3CHINA
W3CHINA Blog 0.8 Processed in 0.063 second(s), page refreshed 144761124 times.
《全国人大常委会关于维护互联网安全的决定》  《计算机信息网络国际联网安全保护管理办法》
苏ICP备05006046号