高手是怎样炼成的:精妙SQL语句先容

如何从一位菜鸟演变成为高手，机动应用的SQL语句是必不可少的。本文收集了部分比拟经典，常用的SQL语句供大家参考，盼看对大家有所帮助。

阐明：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

阐明：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;

阐明：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

阐明：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

阐明：日程安排提前五分钟提示　　

SQL: select * from 日程安排 where datediff('minute',f开端时间,getdate())>5

阐明：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

阐明：--

以下为引用的内容：
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

阐明：--

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

阐明：

从数据库中往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起源）

以下为引用的内容：
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')

阐明：四表联查标题：　　

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 .....

阐明：得到表中最小的未应用的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)