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('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)