SQL技能：疾速控制一些异样精妙的"SQL"语句

SQL技能：疾速控制一些异样精妙的"SQL"语句






精妙的"SQL"语句: .复制表(只复制构造,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) sel ...



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 目的表名：b)


SQL: insert into b(a, b, c) select d,e,f from b; 　


.显示文章、提交人跟最后回复时光


SQL: select a.title,a.username,b.adddate from table a,


(select max(adddate) adddate from table where table.titlea.title) b 　


.阐明：外衔接查问(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


.日程部署提前五分钟提示


SQL: select . from 日程支配 where datediff('minute',f开端时间,getdate()) 5 　　


.两张关系表，删除主表中已经在副表中不的信息


SQL:


delete from info where not exists

( select . from infobz where info.infidinfobz.infid )


.解释：


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.idstudent.id) and 系名称'"&strdepartmentname&"' and 专业名称


'"&strprofessionname&"' order by 性别,生源地,高考总成就。