精妙的"SQL"语句:
◆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
◆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;
◆显示文章、提交人和最后回复时间
SQL: select #,#,# from table a,
(select max(adddate) adddate from table where #=#) b
◆说明:外连接查询(表名1:a 表名2:b)
SQL: select #, #, #, #, #, # from a LEFT OUT JOIN b ON # =
#
◆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
◆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 #=# )
◆说明:
SQL:
SELECT #, #, #, #
FROM TABLE1,(SELECT #, #, #
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 # = #
(+)AND # + NVL(#,0) <>
# ) B WHERE # = #
◆说明:
SQL:
select * from studentinfo where not exists(select * from student where
#=#) and 系名称='"&strdepartmentname&"' and 专业名称
='"&strprofessionname&"' order by 性别,生源地,高考总成绩。