SQL技巧:快速把握一些异常精妙的SQL语句
复制表
SQL: selectinto b from a where 11
拷贝表
SQL: insert into b select d,e,f from b;
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,
adddate from table where table.title=a.title) b
说明:外连接查询
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
日程安排提前五分钟提醒
SQL: selectfrom 日程安排 where datediff)5
两张关联表,删除主表中已经在副表中没有的
SQL:
delete from info where not exists
说明:
SQL:
SELECT A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE
FROM TABLE1, = TO_CHAR) X,
= TO_CHAR ‘/01‘,‘
YYYY/MM/DD‘) - 1, ‘YYYY/MM‘) ) Y, WHERE X.NUM = Y.NUM
(+)AND X.INBOUND_QTY + NVL
X.STOCK_ONHAND ) B WHERE A.NUM = B.NUM
说明:
SQL:
selectfrom studentinfo where not exists and 系名称=‘"strdepartmentname"‘ and 专业名称
=‘"strprofessionname"‘ order by 性别,生源地,高考总成绩。