精妙SQL语句

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(&#39;minute&#39;,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,&#39;YYYY/MM&#39;) = TO_CHAR(SYSDATE, &#39;YYYY/MM&#39;)) X, (SELECT NUM, UPD_DATE, STOCK_ONHAND FROM TABLE2 WHERE TO_CHAR(UPD_DATE,&#39;YYYY/MM&#39;) = TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, &#39;YYYY/MM&#39;) || &#39;/01&#39;,&#39;YYYY/MM/DD&#39;) - 1, &#39;YYYY/MM&#39;) ) 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=&#39;\"&strdepartmentname&\"&#39; and 专业名称=&#39;\"&strprofessionname&\"&#39; 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, &#39;yyyy&#39;) AS telyear, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;01&#39;, a.factration)) AS JAN, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;02&#39;, a.factration)) AS FRI, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;03&#39;, a.factration)) AS MAR, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;04&#39;, a.factration)) AS APR, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;05&#39;, a.factration)) AS MAY, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;06&#39;, a.factration)) AS JUE,SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;07&#39;, a.factration)) AS JUL, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;08&#39;, a.factration)) AS AGU, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;09&#39;, a.factration)) AS SEP, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;10&#39;, a.factration)) AS OCT, SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;11&#39;, a.factration)) AS NOV,SUM(decode(TO_CHAR(a.telfeedate, &#39;mm&#39;), &#39;12&#39;, 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, &#39;yyyy&#39;)

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)