一些暴强的SQL语句
一些暴强的SQL语句 | ||
出处: | 作者: | 发布时间:2008-9-4 |
说明:复制表(只复制结构,源表名:a 新表名:b)
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) 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 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) 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 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 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:-- 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 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) 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 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 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) 一个SQL语句的问题:行列转换 select * from v_temp 上面的视图结果如下: user_name role_name ------------------------- 系统管理员 管理员 feng 管理员 feng 一般用户 test 一般用户 想把结果变成这样: user_name role_name --------------------------- 系统管理员 管理员 feng 管理员,一般用户 test 一般用户 =================== create table a_test(name varchar(20),role2 varchar(20)) insert into a_test values('李','管理员') insert into a_test values('张','管理员') insert into a_test values('张','一般用户') insert into a_test values('常','一般用户') create function join_str(@content varchar(100)) returns varchar(2000) as begin declare @str varchar(2000) set @str='' select @str=@str+','+rtrim(role2) from a_test where [name]=@content select @str=right(@str,len(@str)-1) return @str end go --调用: select [name],dbo.join_str([name]) role2 from a_test group by [name] --select distinct name,dbo.uf_test(name) from a_test 快速比较结构相同的两表 结构相同的两表,一表有记录3万条左右,一表有记录2万条左右,我怎样快速查找两表的不同记录? ============================ 给你一个测试方法,从northwind中的orders表取数据。 select * into n1 from orders select * into n2 from orders select * from n1 select * from n2 --添加主键,然后修改n1中若干字段的若干条 alter table n1 add constraint pk_n1_id primary key (OrderID) alter table n2 add constraint pk_n2_id primary key (OrderID) select orderID from (select * from n1 union select * from n2) a group by orderID having count(*) > 1 应该可以,而且将不同的记录的ID显示出来。 下面的适用于双方记录一样的情况, select * from n1 where orderid in (select orderID from (select * from n1 union select * from n2) a group by orderID having count(*) > 1) 至于双方互不存在的记录是比较好处理的 --删除n1,n2中若干条记录 delete from n1 where orderID in ('10728','10730') delete from n2 where orderID in ('11000','11001') --************************************************************* -- 双方都有该记录却不完全相同 select * from n1 where orderid in(select orderID from (select * from n1 union select * from n2) a group by orderID having count(*) > 1) union --n2中存在但在n1中不存的在10728,10730 select * from n1 where orderID not in (select orderID from n2) union --n1中存在但在n2中不存的在11000,11001 select * from n2 where orderID not in (select orderID from n1) 四种方法取表里n到m条纪录: 1. select top m * into 临时表(或表变量) from tablename order by columnname -- 将top m笔插入 set rowcount n select * from 表变量 order by columnname desc 2. select top n * from (select top m * from tablename order by columnname) a order by columnname desc 3.如果tablename里没有其他identity列,那么: select identity(int) id0,* into #temp from tablename 取n到m条的语句为: select * from #temp where id0 >=n and id0 <= m 如果你在执行select identity(int) id0,* into #temp from tablename这条语句的时候报错,那是因为你的DB中间的select into/bulkcopy属性没有打开要先执行: exec sp_dboption 你的DB名字,'select into/bulkcopy',true |