說明:復(fù)制表(只復(fù)制結(jié)構(gòu),源表名:a 新表名:b) 說明:拷貝表(拷貝數(shù)據(jù),源表名:a 目標表名:b) insert into b(a, b, c) select d,e,f from b; 說明:顯示文章、提交人和最后回復(fù)時間 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) select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 說明:日程安排提前五分鐘提醒 select * from 日程安排 where datediff('minute',f開始時間,getdate())>5 說明:兩張關(guān)聯(lián)表,刪除主表中已經(jīng)在副表中沒有的信息 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') || '/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:-- 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 從數(shù)據(jù)庫中去一年的各單位電話費統(tǒng)計(電話費定額賀電化肥清單兩個表來源) 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') 說明:四表聯(lián)查問題 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 ..... 說明:得到表中最小的未使用的ID號 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) 一個SQL語句的問題:行列轉(zhuǎn)換 select * from v_temp 上面的視圖結(jié)果如下: user_name role_name ------------------------- 系統(tǒng)管理員 管理員 feng 管理員 feng 一般用戶 test 一般用戶 想把結(jié)果變成這樣: user_name role_name --------------------------- 系統(tǒng)管理員 管理員 feng 管理員,一般用戶 test 一般用戶 =================== create table a_test(name varchar(20),role2 varchar(20)) insert into a_test values('李','管理員') insert into a_test values('張','管理員') insert into a_test values('張','一般用戶') insert into a_test values('常','一般用戶') create function join_str(@content varchar(100)) returns varchar(2000) as begin declare @str varchar(2000) set @str='' select @str=@str+','+rtrim(role2) from a_test where [name]=@content select @str=right(@str,len(@str)-1) return @str end go --調(diào)用: select [name],dbo.join_str([name]) role2 from a_test group by [name] --select distinct name,dbo.uf_test(name) from a_test 快速比較結(jié)構(gòu)相同的兩表 結(jié)構(gòu)相同的兩表,一表有記錄3萬條左右,一表有記錄2萬條左右,我怎樣快速查找兩表的不同記錄? ============================ 給你一個測試方法,從northwind中的orders表取數(shù)據(jù)。 select * into n1 from orders select * into n2 from orders select * from n1 select * from n2 --添加主鍵,然后修改n1中若干字段的若干條 |
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