Ejecutar una función definida por el usuario y procesar el código de retorno (OLE DB)
En este ejemplo, se ejecuta una función definida por el usuario y se imprime el código de retorno. Este ejemplo no es compatible con IA64.
Este ejemplo requiere la base de datos de ejemplo AdventureWorks que se puede descargar de la página principal que muestra ejemplos y proyectos de la comunidad de Microsoft SQL Server.
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Ejemplo
Ejecute la primera lista de código (Transact-SQL) para crear el procedimiento almacenado utilizado por la aplicación.
Compile con ole32.lib oleaut32.lib y ejecute la segunda lista de código (C++). Esta aplicación se conecta a la instancia predeterminada de SQL Server del equipo. En algunos sistemas operativos Windows, deberá cambiar (localhost) o (local) al nombre de la instancia de SQL Server. Para conectarse a una instancia con nombre, cambie la cadena de conexión de L"(local)" a L"(local)\\name", donde "name" es la instancia con nombre. De forma predeterminada, SQL Server Express se instala en una instancia con nombre. Asegúrese de que la variable de entorno INCLUDE incluye el directorio que contiene sqlncli.h.
Ejecute la tercera lista de código (Transact-SQL) para eliminar el procedimiento almacenado utilizado por la aplicación.
USE AdventureWorks
if exists (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[fn_RectangleArea]'))
drop function fn_RectangleArea
go
CREATE FUNCTION fn_RectangleArea
(@Width int,
@Height int )
RETURNS int
AS
BEGIN
RETURN ( @Width * @Height )
END
GO
// compile with: ole32.lib oleaut32.lib
void InitializeAndEstablishConnection();
#define UNICODE
#define DBINITCONSTANTS
#define INITGUID
#define OLEDBVER 0x0250 // to include correct interfaces
#include <windows.h>
#include <stdio.h>
#include <stddef.h>
#include <iostream>
#include <oledb.h>
#include <oledberr.h>
#include <sqlncli.h>
using namespace std;
IDBInitialize* pIDBInitialize = NULL;
IDBCreateSession* pIDBCreateSession = NULL;
IDBCreateCommand* pIDBCreateCommand = NULL;
ICommandText* pICommandText = NULL;
IRowset* pIRowset = NULL;
ICommandWithParameters* pICommandWithParams = NULL;
IAccessor* pIAccessor = NULL;
IDBProperties* pIDBProperties = NULL;
WCHAR* pStringsBuffer;
DBBINDING* pBindings;
const ULONG nInitProps = 4;
DBPROP InitProperties[nInitProps];
const ULONG nPropSet = 1;
DBPROPSET rgInitPropSet[nPropSet];
HRESULT hr;
HACCESSOR hAccessor;
const ULONG nParams = 3; // No. of parameters in the command
DBPARAMBINDINFO ParamBindInfo[nParams];
ULONG i;
ULONG cbColOffset = 0;
DB_UPARAMS ParamOrdinals[nParams];
DBROWCOUNT cNumRows = 0;
DBPARAMS Params;
// Declare array of DBBINDING structures, one for each parameter in the command
DBBINDING acDBBinding[nParams];
DBBINDSTATUS acDBBindStatus[nParams];
// The following buffer is used to store parameter values.
typedef struct tagSPROCPARAMS {
long lReturnValue;
long inParam1;
long inParam2;
} SPROCPARAMS;
int main() {
// The command to execute.
WCHAR* wCmdString = L"{? = CALL fn_RectangleArea(?, ?) }";
// WCHAR* wCmdString = L"EXEC ? = fn_RectangleVolume(?, ?)";
SPROCPARAMS sprocparams = {0,5,10};
// All the initialization stuff in a separate function.
InitializeAndEstablishConnection();
// Let us create a new session from the data source object.
if (FAILED(pIDBInitialize->QueryInterface( IID_IDBCreateSession,
(void**) &pIDBCreateSession))) {
cout << "Failed to access IDBCreateSession interface\n";
goto EXIT;
}
if ( FAILED(pIDBCreateSession->CreateSession( NULL,
IID_IDBCreateCommand,
(IUnknown**) &pIDBCreateCommand))) {
cout << "pIDBCreateSession->CreateSession failed\n";
goto EXIT;
}
// Create a Command
if (FAILED(pIDBCreateCommand->CreateCommand( NULL,
IID_ICommandText,
(IUnknown**) &pICommandText))) {
cout << "Failed to access ICommand interface\n";
goto EXIT;
}
// Set the command text.
if (FAILED(pICommandText->SetCommandText(DBGUID_DBSQL, wCmdString))) {
cout << "failed to set command text\n";
goto EXIT;
}
// Describe the command parameters (parameter name, provider specific name
// of the parameter's data type etc.) in an array of DBPARAMBINDINFO
// structures. This information is then used by SetParameterInfo().
ParamBindInfo[0].pwszDataSourceType = L"DBTYPE_I4";
ParamBindInfo[0].pwszName = NULL;
ParamBindInfo[0].ulParamSize = sizeof(long);
ParamBindInfo[0].dwFlags = DBPARAMFLAGS_ISOUTPUT;
ParamBindInfo[0].bPrecision = 11;
ParamBindInfo[0].bScale = 0;
ParamOrdinals[0] = 1;
ParamBindInfo[1].pwszDataSourceType = L"DBTYPE_I4";
ParamBindInfo[1].pwszName = NULL; // L"@inparam1";
ParamBindInfo[1].ulParamSize = sizeof(long);
ParamBindInfo[1].dwFlags = DBPARAMFLAGS_ISINPUT;
ParamBindInfo[1].bPrecision = 11;
ParamBindInfo[1].bScale = 0;
ParamOrdinals[1] = 2;
ParamBindInfo[2].pwszDataSourceType = L"DBTYPE_I4";
ParamBindInfo[2].pwszName = NULL; // L"@inparam2";
ParamBindInfo[2].ulParamSize = sizeof(long);
ParamBindInfo[2].dwFlags = DBPARAMFLAGS_ISINPUT;
ParamBindInfo[2].bPrecision = 11;
ParamBindInfo[2].bScale = 0;
ParamOrdinals[2] = 3;
// Set the parameters information.
if (FAILED(pICommandText->QueryInterface( IID_ICommandWithParameters,
(void**)&pICommandWithParams))) {
cout << "failed to obtain ICommandWithParameters\n";
goto EXIT;
}
if (FAILED(pICommandWithParams->SetParameterInfo( nParams,
ParamOrdinals,
ParamBindInfo))) {
cout << "failed in setting parameter info.(SetParameterInfo)\n";
goto EXIT;
}
// Describe the consumer buffer; initialize the array of DBBINDING structures.
// Each binding associates a single parameter to the consumer's buffer.
for ( i = 0 ; i < nParams ; i++ ) {
acDBBinding[i].obLength = 0;
acDBBinding[i].obStatus = 0;
acDBBinding[i].pTypeInfo = NULL;
acDBBinding[i].pObject = NULL;
acDBBinding[i].pBindExt = NULL;
acDBBinding[i].dwPart = DBPART_VALUE;
acDBBinding[i].dwMemOwner = DBMEMOWNER_CLIENTOWNED;
acDBBinding[i].dwFlags = 0;
acDBBinding[i].bScale = 0;
} // for
acDBBinding[0].iOrdinal = 1;
acDBBinding[0].obValue = offsetof(SPROCPARAMS, lReturnValue);
acDBBinding[0].eParamIO = DBPARAMIO_OUTPUT;
acDBBinding[0].cbMaxLen = sizeof(long);
acDBBinding[0].wType = DBTYPE_I4;
acDBBinding[0].bPrecision = 11;
acDBBinding[1].iOrdinal = 2;
acDBBinding[1].obValue = offsetof(SPROCPARAMS, inParam1);
acDBBinding[1].eParamIO = DBPARAMIO_INPUT;
acDBBinding[1].cbMaxLen = sizeof(long);
acDBBinding[1].wType = DBTYPE_I4;
acDBBinding[1].bPrecision = 11;
acDBBinding[2].iOrdinal = 3;
acDBBinding[2].obValue = offsetof(SPROCPARAMS, inParam2);
acDBBinding[2].eParamIO = DBPARAMIO_INPUT;
acDBBinding[2].cbMaxLen = sizeof(long);
acDBBinding[2].wType = DBTYPE_I4;
acDBBinding[2].bPrecision = 11;
// Let us create an accessor from the above set of bindings.
hr = pICommandWithParams->QueryInterface( IID_IAccessor, (void**)&pIAccessor);
if (FAILED(hr))
cout << "Failed to get IAccessor interface\n";
hr = pIAccessor->CreateAccessor( DBACCESSOR_PARAMETERDATA,
nParams,
acDBBinding,
sizeof(SPROCPARAMS),
&hAccessor,
acDBBindStatus);
if (FAILED(hr))
cout << "failed to create accessor for the defined parameters\n";
// Initialize DBPARAMS structure for command execution. DBPARAMS specifies the
// parameter values in the command. DBPARAMS is then passed to Execute.
Params.pData = &sprocparams;
Params.cParamSets = 1;
Params.hAccessor = hAccessor;
// Execute the command.
if (FAILED(hr = pICommandText->Execute( NULL,
IID_IRowset,
&Params,
&cNumRows,
(IUnknown **) &pIRowset))) {
cout << "failed to execute command\n";
goto EXIT;
}
printf(" Return value = %d\n", sprocparams.lReturnValue);
// Release result set without processing.
if (pIRowset != NULL)
pIRowset->Release();
// Release memory.
pIAccessor->ReleaseAccessor(hAccessor, NULL);
pIAccessor->Release();
pICommandWithParams->Release();
pICommandText->Release();
pIDBCreateCommand->Release();
pIDBCreateSession->Release();
if (FAILED(pIDBInitialize->Uninitialize()))
// Uninitialize is not required, but it fails if an interface
// has not not been released. This can be used for debugging.
cout << "Problem uninitializing\n";
pIDBInitialize->Release();
CoUninitialize();
return 0;
EXIT:
if (pIAccessor != NULL)
pIAccessor->Release();
if (pICommandWithParams != NULL)
pICommandWithParams->Release();
if (pICommandText != NULL)
pICommandText->Release();
if (pIDBCreateCommand != NULL)
pIDBCreateCommand->Release();
if (pIDBCreateSession != NULL)
pIDBCreateSession->Release();
if (pIDBInitialize != NULL)
if (FAILED(pIDBInitialize->Uninitialize()))
// Uninitialize is not required, but it fails if an interface has
// not been released. This can be used for debugging.
cout << "problem in uninitializing\n";
pIDBInitialize->Release();
CoUninitialize();
}
void InitializeAndEstablishConnection() {
// Initialize the COM library.
CoInitialize(NULL);
// Obtain access to the SQL Server native Client OLE DB provider.
hr = CoCreateInstance( CLSID_SQLNCLI11,
NULL,
CLSCTX_INPROC_SERVER,
IID_IDBInitialize,
(void **) &pIDBInitialize);
if (FAILED(hr))
cout << "Failed in CoCreateInstance()\n";
// Initialize the property values needed to establish the connection.
for ( i = 0 ; i < nInitProps ; i++ )
VariantInit(&InitProperties[i].vValue);
// Specify server name.
InitProperties[0].dwPropertyID = DBPROP_INIT_DATASOURCE;
InitProperties[0].vValue.vt = VT_BSTR;
// Replace "MySqlServer" with proper value.
InitProperties[0].vValue.bstrVal = SysAllocString(L"(local)");
InitProperties[0].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties[0].colid = DB_NULLID;
// Specify database name.
InitProperties[1].dwPropertyID = DBPROP_INIT_CATALOG;
InitProperties[1].vValue.vt = VT_BSTR;
InitProperties[1].vValue.bstrVal = SysAllocString(L"AdventureWorks");
InitProperties[1].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties[1].colid = DB_NULLID;
InitProperties[2].dwPropertyID = DBPROP_AUTH_INTEGRATED;
InitProperties[2].vValue.vt = VT_BSTR;
InitProperties[2].vValue.bstrVal = SysAllocString(L"SSPI");
InitProperties[2].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties[2].colid = DB_NULLID;
// Now that properties are set, construct the DBPROPSET structure
// (rgInitPropSet). The DBPROPSET structure is used to pass an array
// of DBPROP structures (InitProperties) to SetProperties method.
rgInitPropSet[0].guidPropertySet = DBPROPSET_DBINIT;
rgInitPropSet[0].cProperties = 4;
rgInitPropSet[0].rgProperties = InitProperties;
// Set initialization properties.
hr = pIDBInitialize->QueryInterface( IID_IDBProperties, (void **)&pIDBProperties);
if (FAILED(hr))
cout << "Failed to obtain IDBProperties interface.\n";
hr = pIDBProperties->SetProperties( nPropSet, rgInitPropSet);
if (FAILED(hr))
cout << "Failed to set initialization properties\n";
pIDBProperties->Release();
// Now we establish connection to the data source.
if (FAILED(pIDBInitialize->Initialize()))
cout << "Problem in initializing\n";
}
USE AdventureWorks
drop function fn_RectangleArea
go
Vea también
Conceptos
Temas de procedimientos de procesamiento de resultados (OLE DB)