Ejecutar una función definida por el usuario y procesar el código de retorno (OLE DB)
Se aplica a:
SQL Server Azure SQL Database Azure SQL Instancia administrada Azure Synapse Analytics Analytics Platform System (PDW)
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.
En este ejemplo se usa la base de datos oledbtest como ejemplo. Sustitúyala por cualquier base de datos de SQL Server que tenga.
Importante
Siempre que sea posible, utilice la autenticación de Windows. Si la autenticación de Windows no está disponible, solicite a los usuarios que escriban sus credenciales en tiempo de ejecución. No guarde las credenciales en un archivo. Si tiene que conservar las credenciales, debería cifrarlas con la API de criptografía de Win32.
Ejemplo
Ejecute la primera lista de códigos (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 en la variable de entorno INCLUDE se incluya el directorio que contiene msoledbsql.h.
Ejecute la tercera lista de códigos (Transact-SQL) para eliminar el procedimiento almacenado utilizado por la aplicación.
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
#include <iostream>
#include <atlbase.h> // CComPtr
#include "msoledbsql.h"
HRESULT InitializeAndEstablishConnection(CComPtr<IDBInitialize>& pIDBInitialize);
HRESULT ExecuteFunction(const CComPtr<IDBInitialize>& pIDBInitialize);
int main()
{
HRESULT hr = S_OK;
// Initialize the COM library.
CoInitialize(nullptr);
// All interfaces must be freed before CoUninitialize is called,
// thus limiting the scope of pIDBInitialize
{
CComPtr<IDBInitialize> pIDBInitialize;
// All the initialization stuff in a separate function.
hr = InitializeAndEstablishConnection(pIDBInitialize);
if (FAILED(hr))
{
std::cout << "Failed to connect\n";
goto EXIT;
}
hr = ExecuteFunction(pIDBInitialize);
if (FAILED(hr))
{
std::cout << "Failed in executing function\n";
goto EXIT;
}
if (FAILED(pIDBInitialize->Uninitialize()))
{
// Uninitialize is not required, but it fails if an interface
// has not been released. This can be used for debugging.
std::cout << "Problem uninitializing\n";
}
}
EXIT:
CoUninitialize();
return (FAILED(hr));
}
HRESULT InitializeAndEstablishConnection(CComPtr<IDBInitialize>& pIDBInitialize)
{
HRESULT hr = S_OK;
// Obtain access to the OLE DB Driver for SQL Server.
hr = CoCreateInstance(CLSID_MSOLEDBSQL,
nullptr,
CLSCTX_INPROC_SERVER,
IID_IDBInitialize,
reinterpret_cast<LPVOID *>(&pIDBInitialize));
if (FAILED(hr))
{
std::cout << "Failed in CoCreateInstance()\n";
return hr;
}
const ULONG nInitProps1 = 3;
const ULONG nInitProps2 = 1;
const ULONG nPropSets = 2;
CComBSTR server(L"(local)");
CComBSTR database(L"oledbtest");
CComBSTR auth(L"SSPI");
CComBSTR encrypt(L"Mandatory");
DBPROP InitProperties1[nInitProps1] = {};
DBPROP InitProperties2[nInitProps2] = {};
DBPROPSET rgInitPropSet[nPropSets] = {};
// Initialize the property values needed to establish the connection.
for (ULONG i = 0; i < nInitProps1; i++)
VariantInit(&InitProperties1[i].vValue);
// Specify server name.
InitProperties1[0].dwPropertyID = DBPROP_INIT_DATASOURCE;
InitProperties1[0].vValue.vt = VT_BSTR;
// Replace "MySqlServer" with proper value.
InitProperties1[0].vValue.bstrVal = server;
InitProperties1[0].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties1[0].colid = DB_NULLID;
// Specify database name.
InitProperties1[1].dwPropertyID = DBPROP_INIT_CATALOG;
InitProperties1[1].vValue.vt = VT_BSTR;
InitProperties1[1].vValue.bstrVal = database;
InitProperties1[1].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties1[1].colid = DB_NULLID;
InitProperties1[2].dwPropertyID = DBPROP_AUTH_INTEGRATED;
InitProperties1[2].vValue.vt = VT_BSTR;
InitProperties1[2].vValue.bstrVal = auth;
InitProperties1[2].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties1[2].colid = DB_NULLID;
// Data should be encrypted before sending it over the network
VariantInit(&InitProperties2[0].vValue);
InitProperties2[0].dwPropertyID = SSPROP_INIT_ENCRYPT;
InitProperties2[0].vValue.vt = VT_BSTR;
InitProperties2[0].vValue.bstrVal = encrypt;
InitProperties2[0].dwOptions = DBPROPOPTIONS_REQUIRED;
InitProperties2[0].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 = nInitProps1;
rgInitPropSet[0].rgProperties = InitProperties1;
rgInitPropSet[1].guidPropertySet = DBPROPSET_SQLSERVERDBINIT;
rgInitPropSet[1].cProperties = nInitProps2;
rgInitPropSet[1].rgProperties = InitProperties2;
// Set initialization properties.
CComPtr<IDBProperties> pIDBProperties;
hr = pIDBInitialize->QueryInterface(IID_IDBProperties,
reinterpret_cast<LPVOID *>(&pIDBProperties));
if (FAILED(hr))
{
std::cout << "Failed to obtain IDBProperties interface.\n";
return hr;
}
hr = pIDBProperties->SetProperties(nPropSets, rgInitPropSet);
if (FAILED(hr)) {
std::cout << "Failed to set initialization properties\n";
return hr;
}
// Now we establish connection to the data source.
if (FAILED(hr = pIDBInitialize->Initialize())) {
std::cout << "Problem in initializing\n";
}
return hr;
}
HRESULT ExecuteFunction(const CComPtr<IDBInitialize>& pIDBInitialize)
{
HRESULT hr = S_OK;
CComPtr<IDBCreateSession> pIDBCreateSession;
// Let us create a new session from the data source object.
if (FAILED(hr = pIDBInitialize->QueryInterface(IID_IDBCreateSession,
reinterpret_cast<LPVOID *>(&pIDBCreateSession))))
{
std::cout << "Failed to access IDBCreateSession interface\n";
return hr;
}
CComPtr<IDBCreateCommand> pIDBCreateCommand;
if (FAILED(hr = pIDBCreateSession->CreateSession(NULL,
IID_IDBCreateCommand,
reinterpret_cast<IUnknown **>(&pIDBCreateCommand))))
{
std::cout << "Failed to obtain IDBCreateCommand interface\n";
return hr;
}
// Create a Command
CComPtr<ICommandText> pICommandText;
if (FAILED(hr = pIDBCreateCommand->CreateCommand(NULL,
IID_ICommandText,
reinterpret_cast<IUnknown **>(&pICommandText))))
{
std::cout << "Failed to access ICommand interface\n";
return hr;
}
// The following buffer is used to store parameter values.
typedef struct tagSPROCPARAMS
{
long lReturnValue;
long inParam1;
long inParam2;
} SPROCPARAMS;
// Set the command text.
if (FAILED(hr = pICommandText->SetCommandText(DBGUID_DBSQL, L"{? = CALL fn_RectangleArea(?, ?) }")))
{
std::cout << "Failed to set command text\n";
return hr;
}
// Set the parameters information.
CComPtr<ICommandWithParameters> pICommandWithParams;
if (FAILED(hr = pICommandText->QueryInterface(IID_ICommandWithParameters,
reinterpret_cast<LPVOID *>(&pICommandWithParams))))
{
std::cout << "Failed to obtain ICommandWithParameters\n";
return hr;
}
const ULONG nParams = 3; // No. of parameters in the command
DBPARAMBINDINFO ParamBindInfo[nParams] = {};
DB_UPARAMS ParamOrdinals[nParams] = {};
DBROWCOUNT cNumRows = 0;
// 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 = const_cast<LPOLESTR>(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 = const_cast<LPOLESTR>(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 = const_cast<LPOLESTR>(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;
if (FAILED(hr = pICommandWithParams->SetParameterInfo(nParams,
ParamOrdinals,
ParamBindInfo)))
{
std::cout << "Failed in setting parameter info.(SetParameterInfo)\n";
return hr;
}
HACCESSOR hAccessor = 0;
SPROCPARAMS sprocparams = {0,5,10};
// Declare array of DBBINDING structures, one for each parameter in the command
DBBINDING acDBBinding[nParams] = {};
// Describe the consumer buffer; initialize the array of DBBINDING structures.
// Each binding associates a single parameter to the consumer's buffer.
for (ULONG 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.
CComPtr<IAccessor> pIAccessor;
hr = pICommandWithParams->QueryInterface(IID_IAccessor,
reinterpret_cast<LPVOID *>(&pIAccessor));
if (FAILED(hr))
{
std::cout << "Failed to get IAccessor interface\n";
return hr;
}
DBBINDSTATUS acDBBindStatus[nParams] = {};
hr = pIAccessor->CreateAccessor(DBACCESSOR_PARAMETERDATA,
nParams,
acDBBinding,
sizeof(SPROCPARAMS),
&hAccessor,
acDBBindStatus);
if (FAILED(hr))
{
std::cout << "Failed to create accessor for the defined parameters\n";
return hr;
}
// Initialize DBPARAMS structure for command execution. DBPARAMS specifies the
// parameter values in the command. DBPARAMS is then passed to Execute.
DBPARAMS Params = {nullptr, 0, 0};
Params.pData = &sprocparams;
Params.cParamSets = 1;
Params.hAccessor = hAccessor;
// Execute the command.
if (SUCCEEDED(hr = pICommandText->Execute(nullptr,
IID_NULL,
&Params,
&cNumRows,
nullptr)))
{
printf("Return value = %d\n", sprocparams.lReturnValue);
}
else
{
std::cout << "Failed to execute command\n";
}
// Release memory.
pIAccessor->ReleaseAccessor(hAccessor, nullptr);
return hr;
}
drop function fn_RectangleArea
go
Consulte también
Temas de procedimientos de procesamiento de resultados (OLE DB)
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