uses
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Inifile;
var
ini:tinifile;
SqlServer,Sqlusr,SqlPwd:string;
begin
ini:=tinifile.create('My.ini');
SqlServer
:=ini.ReadString('Server','SqlServer','');
//读取INI配置文件服务器IP地址
Sqlusr
:=ini.ReadString('Server','Sqlusr','');
//读取INI配置文件SQL账号
SqlPwd
:=ini.ReadString('Server','Sqlpwd','');
//读取INI配置文件SQL密码
//然后使用ADOquery将账号密码加入后连接就可以了
end;
ini配置文件：
[Server]
SqlServer=127.0.0.1
Sqlusr=sa
Sqlpwd=123456
嵌套比较多，你慢慢看。
select D.address, D.time, D.value
from (select A.address, A.time, A.value
from A
union
select B.address, B.time, B.value
from B) D,
(select C.Address, max(C.time) as maxTime
from (select A.address, A.time, A.value
from A
union
select B.address, B.time, B.value
from B) C
group by C.address) E
where D.address = E.address
and D.time = E.maxTime
代码是最好的文字，不多说，请看我的代码，并给分，呵呵。
--step1. 建表
if exists(select * from sysobjects where id=object_id('student') and objectproperty(id,'IsTable')=1)
drop table student
go
create table student
(
id int identity(100,10) not null
,sname varchar(10) not null
,sno varchar(30) not null
)
go
--step2.建存储过程
if exists(select * from sysobjects where id=object_id('proc_demo') and objectproperty(id,'IsProcedure')=1)
drop procedure proc_demo
go
create procedure proc_demo
@o_maxid int output
as
set nocount on
--如果希望大小写敏感，使用第一句，因为SQL Server默认是大小写不敏感的
--update student set sno='cay_'+sno where ascii(substring(sname,1,1))=87 and ascii(substring(sname,2,1))=65 and sno not like 'cay_%'
update student set sno='cay_'+sno where sname like 'WA%' and sno not like 'cay_%'
print convert(varchar(10),@@rowcount)+'条记录符合条件并被处理'
select @o_maxid=max(id) from student where id=100
if(@o_maxid is null) print '没有找到符合条件的最大记录'
set nocount off
go
--测试数据1
truncate table student
set identity_insert student on
insert into student(id,sname,sno)values(1,'WA1','1');
insert into student(id,sname,sno)values(2,'wa2','2');
insert into student(id,sname,sno)values(3,'3','3');
set identity_insert student off
go
--测试数据2
truncate table student
insert into student(sname,sno)values('WA1','1');
insert into student(sname,sno)values('wa2','2');
insert into student(sname,sno)values('3','3');
go
--测试过程
declare @maxid int
exec proc_demo @maxid out
print '最大id是'+convert(varchar(10),@maxid)
go
