请大家帮忙看看这段ADO程序，多谢！

[oceanwhh]

在ADO中使用COMMAND来执行一个带有输出参数的存储过程，在数据库中执行有输出参数值，但是ADO中的输出参数为0，代码如下：
_ConnectionPtr pConn;
_CommandPtr pComm;
_RecordsetPtr pRs;

pConn.CreateInstance("ADODB.Connection");
pComm.CreateInstance("ADODB.Command");
pRs.CreateInstance("ADODB.Recordset");

//connect DB;
pConn->Open("DATABASE","sa","",adModeUnknown);

//exe sql;
pComm->ActiveConnection=pConn;
pComm->CommandText="MYPROC";
pComm->CommandType=adCmdStoredProc;

_ParameterPtr outParam=pComm->CreateParameter(_bstr_t ("maxid"),adInteger,adParamOutput,sizeof(int));
pComm->Parameters->Append(outParam);

pRs=pComm->Execute(NULL,NULL,adCmdStoredProc);

long out=pComm->Parameters->Item[(short)0]->Value;
CString str;
str.Format("maxid is %d",out);
AfxMessageBox(str);

存储过程如下：
CREATE procedure MYPROC
@maxid int output
as
select @maxid=( max(id)) from temp;

[pengdali]

below is from MSDN,you can find a lot of technical article in MSDN if you search"stored procedure and VC"
good luck

Steps To Reproduce Behavior
In the SQL Server 7.0 Query Analyzer select the test database Pubs.


Create the following stored procedure. This stored procedure returns a recordset and an out parameter count.



if exists (select * from sysobjects where id = object_id(N'[dbo].[GetJobs]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop proc GetJobs
go
create proc GetJobs @id as int, @count as int [out] as
begin
Select @count = Count(*) from jobs where job_id >@id
Select * from jobs where job_id >@id
end
go




Use VC App Wizard to create a new console application and modify the code as follows:



#include "stdafx.h"
#include "stdio.h"
#import "C:\PROGRA~1\COMMON~1\System\ado\msado15.dll" no_namespace rename ("EOF", "EOF2")

struct InitOle {
InitOle() { ::CoInitialize(NULL); }
~InitOle() { ::CoUninitialize(); }
} _init_InitOle_;

int main(int argc, char* argv[])
{
_variant_t varErr((long)0, VT_ERROR);
_CommandPtr comm(__uuidof(Command));
_ConnectionPtr conn(__uuidof(Connection));

_bstr_t connstr="Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initial Catalog=pubs;Data Source=(local)";
conn->Open(connstr, "", "", adConnectUnspecified);
comm->ActiveConnection=conn;
comm->CommandText="GetJobs";
comm->CommandType = adCmdStoredProc ;
comm->Parameters->Refresh();
_variant_t recs;

comm->Parameters->Item[_variant_t((short)1)]->Value= _variant_t((long)5);
_RecordsetPtr rs = comm->Execute(&recs, &vtMissing,adCmdStoredProc);

_variant_t recordcount= comm->Parameters->Item[_variant_t((short)2)]->Value;

printf("recordcount = %li\n", (long)recordcount);
return 0;
}



Change the Datasource, User ID and password in the connection string above.




The recordcount variant that the above code returns is of type VT_NULL rather than the number of records that the stored procedure returns.

[zjcxc]

试试:
_ConnectionPtr pConn;
_CommandPtr pComm;
_RecordsetPtr pRs;

pConn.CreateInstance("ADODB.Connection");
pComm.CreateInstance("ADODB.Command");
pRs.CreateInstance("ADODB.Recordset");

//connect DB;
pConn->Open("DATABASE","sa","",adModeUnknown);

//exe sql;
pComm->ActiveConnection=pConn;
pComm->CommandText="MYPROC";
pComm->CommandType=adCmdStoredProc;

pComm->Parameters->Refresh

pRs=pComm->Execute(NULL,NULL,adCmdStoredProc);

long out=pComm->Parameters->Item["@maxid"]->Value;
CString str;
str.Format("maxid is %d",out);
AfxMessageBox(str);