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/') ¦¦ /'/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)
