Eseguire una funzione definita dall'utente di SQL Server Native Client e un codice restituito del processo (OLE DB)
Si applica a:
SQL ServerDatabase SQL diAzure Istanzagestita di SQL di Azure Azure Synapse Analytics PlatformSystem (PDW)
In questo esempio viene eseguita una funzione definita dall'utente e viene stampato il codice restituito. Questo esempio non è supportato in IA64.
Questo articolo richiede il AdventureWorks2022 database di esempio, che è possibile scaricare dalla home page degli esempi di Microsoft SQL Server e dei progetti della community.
Importante
Se possibile, usare l'autenticazione di Windows. Se non è disponibile, agli utenti verrà richiesto di immettere le credenziali in fase di esecuzione. Evitare di archiviare le credenziali in un file. Se è necessario rendere persistenti le credenziali, è consigliabile crittografarle usando l'API di crittografia Win32.
Esempio
Eseguire il primo elenco codici (Transact-SQL) per creare la stored procedure usata dall'applicazione.
Compilare il secondo listato di codice (C++) con ole32.lib oleaut32.lib ed eseguirlo. In questa applicazione viene eseguita la connessione all'istanza predefinita di SQL Server nel computer in uso. In alcuni sistemi operativi Windows sarà necessario modificare (local) o (localhost) impostando il valore sul nome dell'istanza di SQL Server. Per connettersi a un'istanza denominata, modificare la stringa di connessione da L"(local)" a L"(local)\name" , dove name è l'istanza denominata. Per impostazione predefinita, SQL Server Express viene installato in un'istanza denominata. Verificare che nella variabile di ambiente INCLUDE sia presente la directory che contiene sqlncli.h.
Eseguire il terzo elenco codici (Transact-SQL) per eliminare la stored procedure usata dall'applicazione.
USE AdventureWorks2022;
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 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 AdventureWorks2022;
drop function fn_RectangleArea
go
Vedi anche
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