在vc中通过ado如何读取sqlserver的存储过程的返回值?
存储过程可以通过output返回一些参数,而它本身也可以通过return一个int来返回一些信息。前者我可以得到,但是后者我不会。怎么读取?
以下是读取output参数的返回值的例子,谁能给我读取存储过程通过return得到的值?
vtTemp="";
_ParameterPtr=m_pCmd->CreateParameter("retstring",adChar,adParamOutput,10,vtTemp);
m_pCmd->Parameters->Append(_ParameterPtr);
m_pCmd->ActiveConnection = m_pConnection;//将建立的连接赋值给它
m_pCmd->Execute(NULL,NULL,adCmdStoredProc);///执行命令
问题点数:100、回复次数:4Top
1 楼masterz(www.fruitfruit.com)回复于 2002-03-27 11:16:12 得分 0
// SQL Server, stored procedure , Command , Recordset, input parameter, output parameter, returned recordset from stored procedure
//execute stored procedure , get returned value, output value, and returned recordset.
#include "stdafx.h"
#import "C:\PROGRA~1\COMMON~1\System\ado\msado15.dll" rename( "EOF", "adoEOF" )
struct InitOle
{
InitOle() { ::CoInitialize(NULL); }
~InitOle() { ::CoUninitialize(); }
} _init_InitOle_;
void PrintProviderError(ADODB::_ConnectionPtr pConnection);
int main(int argc, char* argv[])
{
printf("Create a adParamReturnValue for Command object to get return value of stored procedure\n");
printf("Reference :MSDN---Append and CreateParameter Methods Example (VC++)\n");
ADODB::_ConnectionPtr Conn1;
ADODB::_CommandPtr Cmd1;
ADODB::_RecordsetPtr Rs1;
ADODB::_ParameterPtr retParam= NULL;
ADODB::_ParameterPtr inParam=NULL;
ADODB::_ParameterPtr outParam=NULL;
_variant_t vtEmpty (DISP_E_PARAMNOTFOUND, VT_ERROR);
_variant_t vtEmpty2 (DISP_E_PARAMNOTFOUND, VT_ERROR);
_bstr_t bstrConnect( L"driver={sql server};server=Cell;Database=zhg;UID=sa;PWD=;" );
// the following stored procedure return 12345 int value
_bstr_t bstrCreate ( L"create proc sp_AdoTest( @OutParam int OUTPUT,@InParam int ) "
L"as "
L"select @OutParam = @InParam + 10 "
L"select * from Table1"
L"return 12345" );
_bstr_t bstrSP(L"sp_Adotest" );
try
{
_bstr_t bstrEmpty;
Conn1.CreateInstance( __uuidof( ADODB::Connection ) );
Cmd1.CreateInstance( __uuidof( ADODB::Command ) );
Rs1.CreateInstance(__uuidof(ADODB::Recordset));
// Establish connection.
Conn1->ConnectionString = bstrConnect;
Conn1->Open( bstrConnect, bstrEmpty, bstrEmpty, -1 );
// Open recordset.
Cmd1->ActiveConnection = Conn1;
Cmd1->CommandText = bstrSP;
Cmd1->CommandType = ADODB::adCmdStoredProc;
retParam=Cmd1->CreateParameter(_bstr_t("Return"),ADODB::adInteger,ADODB::adParamReturnValue,sizeof(int));
Cmd1->Parameters->Append(retParam);
outParam = Cmd1->CreateParameter(_bstr_t("OutParam"),ADODB::adInteger,ADODB::adParamOutput,sizeof(int));
Cmd1->Parameters->Append(outParam);
inParam = Cmd1->CreateParameter(_bstr_t("InParam"),ADODB::adInteger,ADODB::adParamInput,sizeof(int),_variant_t( (long) 10 ));
inParam->Value=_variant_t( (long) 10 );
Cmd1->Parameters->Append(inParam);
Cmd1->Parameters->Refresh();
Cmd1->Parameters->Item[ _variant_t( _bstr_t("@InParam") ) ]->Value =_variant_t( (long) 11 );
Rs1->put_CursorLocation(ADODB::adUseClient);
Rs1->Open((_variant_t((IDispatch *) Cmd1)),vtEmpty,ADODB::adOpenStatic,
ADODB::adLockReadOnly, -1);
// Get return value of the stored procedure.adCmdUnknown
TCHAR tcbuf[1024];
long retvalue=Cmd1->Parameters->Item[(short)0]->Value;
long p2=Cmd1->Parameters->Item[(short)1]->Value;
long p3=Cmd1->Parameters->Item[(short)2]->Value;
int recordcount=0;
if(Rs1->State==ADODB::adStateClosed)
MessageBox(NULL,"no recordset is returned from the stored procedure","Information",MB_OK);
else
recordcount = Rs1->GetRecordCount();
wsprintf(tcbuf,"retvalue of the stored procedure:%d,input value:%d,output value:%d,record count :%d",retvalue,p2,p3,recordcount);
MessageBox(NULL,tcbuf,"Output",MB_OK);
}
catch(_com_error &e)
{
_bstr_t bstrSource(e.Source());
_bstr_t bstrDescription(e.Description());
printf("\nCOM error occurred, Source : %s \n Description : %s \n",(LPCSTR)bstrSource,(LPCSTR)bstrDescription);
PrintProviderError(Conn1);
}
return 0;
}
VOID PrintProviderError(ADODB::_ConnectionPtr pConnection)
{
// Print Provider Errors from Connection object.
// pErr is a record object in the Connection's Error collection.
ADODB::ErrorPtr pErr = NULL;
long nCount = 0;
long i = 0;
if( (pConnection->Errors->Count) > 0)
{
nCount = pConnection->Errors->Count;
// Collection ranges from 0 to nCount -1.
for(i = 0; i < nCount; i++)
{
pErr = pConnection->Errors->GetItem(i);
printf("\n\t Error number: %x\t%s", pErr->Number, (LPCSTR)pErr->Description);
}
}
}Top
2 楼ZHENG017()回复于 2002-03-27 13:43:35 得分 100
RecordsetPtr ptr;
ptr.CreateInstance(__(uuidof(Recordset));
....
ptr=m_pCmd->Execute(NULL,NULL,adCmdStoredProc);
_variant_t thereturnvalue=ptr->GetCollect (COleVariant((short)0));Top
3 楼masterz(www.fruitfruit.com)回复于 2002-03-27 13:51:15 得分 0
你点贴子后面的管理,我已经作了答复,不知为什么不显示出来Top
4 楼yins(我是土人)回复于 2002-03-27 14:02:21 得分 0
upTop
5 楼wnchg(温水青蛙)回复于 2002-04-21 16:00:21 得分 0
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