求教一个SQL语句写法

MYSQL 数据库SQL语句写法如下：select login_name, count(*) as counts from loginlogs group by login_name order by counts desc limit 0,10 MSSQL 或Access数据库SQL语句写法如下：select top 10 login_name, count(*) as counts from loginlogs group by login_name order by counts desc ...

select * from 成绩表 where 学生id in (select top 1 学生id from 成绩表 where 学科='数学' order by 成绩) and 学科 in ('化学','物理')

select (min) 序号,门牌,住户 from T GROUP BY 门牌,住户

sql="select * from 表 where 订单号='10002'"rs.open sql,conn,1,3 if rs.eof then'如果不存在订单号为10002的数据 rs.addnew'添加 end '存在就更新 rs("a")="11"rs.update rs.close set rs=nothing

新建一个表 CREATE TABLE [dbo].[copy_t]([n] [int] NOT NULL,PRIMARY KEY CLUSTERED ([n] ASC ))插入数据是1到1W，目的是用来分割固定格式的字符串成表形式，速度上不错，以前一个老外DBA来公司培训的时候交的 1.用表变量 declare @table table ([票据ID] [varchar](100) NOT NULL,[...

提供以下3个写法供参考：select * from 原表名 where A in(select A from 原表名 where B=2);select a.* from 原表名 a,(select distinct a from 原表名 where B=2)b where a.A=b.A;select a.* from 原表名 a where exists(select 1 from 原表名 b where a.A=b.A and b...

select t.id,t1.name,t1.age,t2.adress,t2.sexfrom(select id from t1unionselect id from t2) tleft join t1 on t.id=t1.idleft join t2 on t.id=t2.id

select a.* from hyxf a,(select hybh,max(rq) as rq from hyxf group by hybh) b where a.hybh=b.hybh and a.rq=b.rq 正确答案

select A.P_name,A.p_price,B.UEE_price from tb_products A inner join tb_UEExtras B on A.UEE_ProductID=B.UEE_ProductID WHERE A.UEE_ProductID =2638

select top 10 A from table order by A desc 将A列从大到小排序，取出前十行数据 select * from table where A in (select top 10 A from table order by A desc )将所有A列数值等于取出最大十个数值的数据全部查找出来 select top 10 A from （select distinct A from table ）T order...