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📄 adocore.cpp

📁 vc ADO 连接数据库
💻 CPP
📖 第 1 页 / 共 2 页
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        catch(...)
        {
            UnknownErrorEx( List1, Conn1 );
        }

        // Better check that HRESULT!
        if( FAILED( hr ) )
        {
            List1.AddString("*** Failed HRESULT ***" );
            strTmp = LogCrackHR( hr );
            List1.AddString( strTmp );

            // Dump Errors Collection, since if no exception was raised
            // This is only way we can get at it!
            if( Conn1 != NULL )
            {
                AdoErrorEx( List1, Conn1 );
            }
        }

        //----------------------------------
        // Miscellaneous (graceful) Cleanup
        // with quiet error trapping
        //----------------------------------

        // Close any open objects
        if( Rs1                != NULL ) LOGQ( Rs1->Close();   )
        if( Conn1              != NULL ) LOGQ( Conn1->Close(); )

        // Force Release of objects;
        if( Fld1    != NULL ) LOGQ( Fld1->Release();    )
        if( Flds1   != NULL ) LOGQ( Flds1->Release();   )
        if( Rs1     != NULL ) LOGQ( Rs1->Release();     )
        if( Props1  != NULL ) LOGQ( Props1->Release();  )
        if( Cmd1    != NULL ) LOGQ( Cmd1->Release();    )
        if( Conn1   != NULL ) LOGQ( Conn1->Release();   )
    }


    void CodeTemplate( CHorzListBox &List1 )
    {  
       // Using the helper routines, this shows what a typical
       // code fragment using ADO would need in order to provide
       // accurate error handling.  

        ADOConnection*  Conn1   = NULL;
   
        HRESULT         hr      = S_OK;
        CString         strTmp;

        // Trap any error/exception
        try
        {
            //----------------------------------
            // (Fail To) Open Connection Object
            //----------------------------------
            
            // Warm & Fuzzy for user
            List1.ResetContent();
            List1.AddString( "ADO Code Template..." );
            List1.AddString( "\t...Deliberately opening conneciton object with no connection information to generate an error" );
   
            // Create Connection Object(1.5 Version)
            hr = CoCreateInstance( CLSID_CADOConnection, 
                                   NULL, 
                                   CLSCTX_INPROC_SERVER, 
                                   IID_IADOConnection, 
                                   (LPVOID *) &Conn1 );
            if( SUCCEEDED( hr ) ) hr = Conn1->Open( bstrEmpty, bstrEmpty, bstrEmpty, -1 );

            //----------------------
            // YOUR CODE GOES HERE!
            //----------------------

            // Successful Shutdown

        }
        // Catch Blocks
        catch( CException *e )
        {
            MfcErrorEx( e, List1, Conn1 );
        }
        catch( SEH_Exception &e )
        {
            Win32ErrorEx( e, List1, Conn1 );
        }
        catch(...)
        {
            UnknownErrorEx( List1, Conn1 );
        }

        // Better check that HRESULT!
        if( FAILED( hr ) )
        {
            List1.AddString("*** Failed HRESULT ***" );
            strTmp = LogCrackHR( hr );
            List1.AddString( strTmp );

            // Dump Errors Collection, since if no exception was raised
            // This is only way we can get at it!
            if( Conn1 != NULL )
            {
                AdoErrorEx( List1, Conn1 );
            }
        }

        //----------------------------------
        // Miscellaneous (graceful) Cleanup
        // with quiet error trapping
        //----------------------------------

        // Close any open objects
        if( Conn1              != NULL ) LOGQ( Conn1->Close(); )

        // Force Release of objects;
        if( Conn1   != NULL ) LOGQ( Conn1->Release();   )
    }


    void InputOutputReturnParams( CHorzListBox &List1 )
    {  
        ADOConnection*  Conn1   = NULL;
        ADOCommand*     Cmd1    = NULL;
        ADOParameters*  Params1 = NULL;
        ADOParameter*   Param1  = NULL;
        ADORecordset*   Rs1Tmp  = NULL;
        ADOFields*      Flds1   = NULL;
        ADOField*       Fld1    = NULL;

        CString         strTmp;
        CString         SQLServerName;

        long            nCount;

        BSTR            bstrSQLServerConnect = NULL;

        VARIANT_BOOL    bEOF    = VARIANT_FALSE;
        HRESULT         hr      = S_OK;
        COleVariant     v1;

        // Trap any error/exception
        try
        {
            //-------------------------------------
            // Determine SQL Server to Connect too
            //-------------------------------------

            CInputBox   dlg;

            if( dlg.DoModal() == IDOK )
            {
                if( dlg.m_Path.GetLength() == 0 )
                    return;

                CString strTmp;


                strTmp.Format( "driver={sql server};"
                               "server=%s;"
                               "Database=pubs;UID=sa;PWD=;",
                               dlg.m_Path );

                SQLServerName = dlg.m_Path;

                bstrSQLServerConnect = strTmp.AllocSysString();
            }

            //------------------------
            // Open Connection Object
            //------------------------

            // Warm & Fuzzy for user
            List1.ResetContent();
            List1.AddString( "Demonstrating Return, Input and Output parameters..." );
            strTmp.Format( "\t...Assumes SQL Server named %s", SQLServerName );
            List1.AddString( strTmp );
            List1.AddString( "\t...With Error Handling Using Connection Object" );
            List1.AddString( "\t...uses stored procedure sp_AdoTest" );

            // Create Connection Object (1.5 Version )
            hr = CoCreateInstance( CLSID_CADOConnection, 
                                   NULL, 
                                   CLSCTX_INPROC_SERVER, 
                                   IID_IADOConnection, 
                                   (LPVOID *) &Conn1 );
            if( SUCCEEDED( hr ) ) hr = Conn1->put_ConnectionString( bstrSQLServerConnect );
            if( SUCCEEDED( hr ) ) hr = Conn1->Open( bstrEmpty, bstrEmpty, bstrEmpty, -1 );

            //--------------------------
            // Create Stored Procedures
            //--------------------------

            if( SUCCEEDED( hr ) ) List1.AddString( "Creating Stored Procedure..." );

            // Drop Procedure
            if( SUCCEEDED( hr ) ) hr = Conn1->Execute( bstrSQLDrop, &vtEmpty, adCmdText, &Rs1Tmp );
            if( Rs1Tmp != NULL )   // Paranoia!
            {
                Rs1Tmp->Release();
                Rs1Tmp = NULL;
            }
        
            // Create Procedure
            if( SUCCEEDED( hr ) ) hr = Conn1->Execute( bstrSQLCreate, &vtEmpty, adCmdText, &Rs1Tmp );
            if( Rs1Tmp != NULL )   // Paranoia!
            {
                Rs1Tmp->Release();
                Rs1Tmp = NULL;
            }

            //-----------------------------------
            // Open Parameterized Command Object
            //-----------------------------------

            if( SUCCEEDED( hr ) ) List1.AddString( "Opening a ForwardOnly Recordset from a Parameterized Command Object..." );
            if( SUCCEEDED( hr ) ) List1.AddString( "...creating command object" );

            // Create Command Object
            if( SUCCEEDED( hr ) ) hr = CoCreateInstance( CLSID_CADOCommand, 
                                                         NULL, 
                                                         CLSCTX_INPROC_SERVER, 
                                                         IID_IADOCommand, 
                                                         (LPVOID *) &Cmd1 );
            if( SUCCEEDED( hr ) ) hr = Cmd1->putref_ActiveConnection( Conn1 );
            if( SUCCEEDED( hr ) ) hr = Cmd1->put_CommandText( bstrStoredProc ); 
            if( SUCCEEDED( hr ) ) hr = Cmd1->put_CommandType( adCmdStoredProc );

            // Fill Parameters Collection
            List1.AddString( "...refreshing parameters collection off stored procedure" );
            if( SUCCEEDED( hr ) ) hr = Cmd1->get_Parameters( &Params1 );
            if( SUCCEEDED( hr ) ) hr = Params1->Refresh();
            if( SUCCEEDED( hr ) ) hr = Params1->get_Item( COleVariant((long) 1 ), &Param1 );
            if( SUCCEEDED( hr ) ) hr = Param1->put_Value( COleVariant((long) 10 ) );

            // Limit scope of Recordset object (so later we can easily fetch ret/out params)
            List1.AddString( "...opening Recordset" );
            {
                ADORecordset*   Rs1     = NULL;

                // Open Recordset
                if( SUCCEEDED( hr ) ) hr = Cmd1->Execute( &vtEmpty, &vtEmpty2, adCmdStoredProc, &Rs1 );
 
                // Dump the recordset
                if( SUCCEEDED( hr ) ) List1.AddString( "...Dumping Recordset" );
                if( SUCCEEDED ( hr ) ) hr = Rs1->get_Fields( & Flds1 );
                if( SUCCEEDED ( hr ) ) hr = Flds1->get_Count( &nCount );
                if( SUCCEEDED( hr ) ) hr = Rs1->get_EOF( &bEOF );
                while ( ( SUCCEEDED( hr ) ) && ( bEOF == VARIANT_FALSE ) )
                {
                    CString s;
                    strTmp = "\t";

                    // Refresh Fields Collection
                    if( SUCCEEDED( hr ) ) hr = Flds1->Refresh();

                    // Dump Fields Collection
                    for( long l = 0; ( SUCCEEDED( hr ) && (l < nCount)); l++ )
                    {
                        if( SUCCEEDED ( hr ) ) hr = Flds1->get_Item( COleVariant( (long) l ), &Fld1 );

                        if( SUCCEEDED ( hr ) ) hr = Fld1->get_Value( &v1 );
                        if( SUCCEEDED ( hr ) )
                        {
                            Fld1->Release();
                            Fld1 = NULL;
                        }

                        if( l != ( nCount - 1 ) )
                            s.Format( "%s | ", CrackStrVariant( v1 ) );
                        else
                           s.Format( "%s", CrackStrVariant( v1 ) );

                        strTmp += s;
                    }

                    // Add record
                    if( SUCCEEDED( hr ) ) List1.AddString( strTmp );

                    // MoveNext
                    if( SUCCEEDED( hr ) ) hr = Rs1->MoveNext();
                    if( SUCCEEDED( hr ) ) hr = Rs1->get_EOF( &bEOF );
                }

                if( SUCCEEDED( hr ) ) Rs1->Close();
    // Not necessary for return parametrs
    //            if( SUCCEEDED( hr ) ) Rs1->Release();
    //            if( SUCCEEDED( hr ) ) Rs1 = NULL;
            }

            // Display Parameters Collection (with caveat for user)
            if( SUCCEEDED( hr ) ) List1.AddString( "...It is strictly Driver/Provider dependent whether you have to close" ); 
            if( SUCCEEDED( hr ) ) List1.AddString( "the recordset to retrieve output/return parameters.  With the release of" ); 
            if( SUCCEEDED( hr ) ) List1.AddString( "of the SQL Server ODBC Driver with ODBC 3.X, you have to close the recordset." );
            if( SUCCEEDED( hr ) ) List1.AddString( "Previous versions of this driver did not have this requirement, which itself" );
            if( SUCCEEDED( hr ) ) List1.AddString( "came about as part of a bug fix in previous versions of the driver." ); 

            if( SUCCEEDED( hr ) ) hr = Cmd1->get_Parameters( &Params1);

            // Get first parameter
            if( SUCCEEDED( hr ) ) hr = Params1->get_Item( COleVariant( (long) 0 ), &Param1 );
            if( SUCCEEDED( hr ) ) hr = Param1->get_Value( &v1 );
            if( SUCCEEDED( hr ) ) strTmp.Format( "\tRetVal Param = %s", CrackStrVariant( v1 ) );
            if( SUCCEEDED( hr ) ) List1.AddString( strTmp );

            // Get second parameter
            if( SUCCEEDED( hr ) ) hr = Params1->get_Item( COleVariant( (long) 1 ), &Param1 );
            if( SUCCEEDED( hr ) ) hr = Param1->get_Value( &v1 );
            if( SUCCEEDED( hr ) ) strTmp.Format( "\tRetVal Param = %s", CrackStrVariant( v1 ) );
            if( SUCCEEDED( hr ) ) List1.AddString( strTmp );

            // Get third parameter
            if( SUCCEEDED( hr ) ) hr = Params1->get_Item( COleVariant( (long) 2 ), &Param1 );
            if( SUCCEEDED( hr ) ) hr = Param1->get_Value( &v1 );
            if( SUCCEEDED( hr ) ) strTmp.Format( "\tRetVal Param = %s", CrackStrVariant( v1 ) );
            if( SUCCEEDED( hr ) ) List1.AddString( strTmp );
        }
        // Catch Blocks
        catch( CException *e )
        {
            MfcErrorEx( e, List1, Conn1 );
        }
        catch( SEH_Exception &e )
        {
            Win32ErrorEx( e, List1, Conn1 );
        }
        catch(...)
        {
            UnknownErrorEx( List1, Conn1 );
        }

        // Better check that HRESULT!
        if( SUCCEEDED( hr ) )
        {
            List1.AddString( "*** Success! ***" );
        }
        else
        {
            List1.AddString("*** Failed HRESULT ***" );
            strTmp = LogCrackHR( hr );
            List1.AddString( strTmp );

            // Dump Errors Collection, since if no exception was raised
            // This is only way we can get at it!
            if( Conn1 != NULL )
            {
                AdoErrorEx( List1, Conn1 );
            }
        }

        //----------------------------------
        // Miscellaneous (graceful) Cleanup
        // with quiet error trapping
        //----------------------------------

        // Close any open objects
        if( Conn1              != NULL ) LOGQ( Conn1->Close(); )

        // Force Release of objects;
        if( Fld1    != NULL ) LOGQ( Fld1->Release();    )
        if( Flds1   != NULL ) LOGQ( Flds1->Release();   )
        if( Rs1Tmp  != NULL ) LOGQ( Rs1Tmp->Release();  )
        if( Param1  != NULL ) LOGQ( Param1->Release();  )
        if( Params1 != NULL ) LOGQ( Params1->Release(); )
        if( Cmd1    != NULL ) LOGQ( Cmd1->Release();    )
        if( Conn1   != NULL ) LOGQ( Conn1->Release();   )

        // Release BSTR
        if( bstrSQLServerConnect != NULL ) LOGQ( SysFreeString( bstrSQLServerConnect ); )
    }


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