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精妙的"SQL"語句:

◆復(fù)制表(只復(fù)制結(jié)構(gòu),源表名：a 新表名：b)

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

◆拷貝表(拷貝數(shù)據(jù),源表名：a 目標(biāo)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(fù)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 　

◆說明：外連接查詢(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)在副表中沒有的信息

SQL:

delete from info where not exists

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

◆說明：

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

◆說明：

SQL:

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

studentinfo.id=student.id) and 系名稱='"&strdepartmentname&"' and 專業(yè)名稱

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

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