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幫助中心 >  技術(shù)知識庫 >  數據庫 >  相關(guān)技術(shù)支持 >  SQL技巧:快速掌握一些異常精妙的"SQL"語(yǔ)句

SQL技巧:快速掌握一些異常精妙的"SQL"語(yǔ)句

2009-11-16 14:49:22 6942

◆復制表(只復制結構,源表名:a 新表名:b)

SQL: select * into b from a where 1<>1


  


◆拷貝表(拷貝數據,源表名:a 目標表名:b)

SQL: insert into b(a, b, c) select d,e,f from b;  

◆顯示文章、提交人和最后回復時(shí)間

SQL: select a.title,a.username,b.adddate from table a,


(select max(adddate) adddate from table where table.title=a.title) b  

◆說(shuō)明:外連接查詢(xún)(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

◆日程安排提前五分鐘提醒

SQL: select * from 日程安排 where datediff(minute,f開(kāi)始時(shí)間,getdate())>5   

◆兩張關(guān)聯(lián)表,刪除主表中已經(jīng)在副表中沒(méi)有的信息

SQL:


delete from info where not exists

( select * from infobz where info.infid=infobz.infid )

◆說(shuō)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

  


◆說(shuō)明:

SQL:


select * from studentinfo where not exists(select * from student where


studentinfo.id=student.id) and 系名稱(chēng)="&strdepartmentname&" and 專(zhuān)業(yè)名稱(chēng)


="&strprofessionname&" order by 性別,生源地,高考總成績(jì)。

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