Acessar dados do FILESTREAM com OpenSqlFilestreamAccess FILESTREAM Data with OpenSqlFilestream

APLICA-SE A: simSQL Server nãoBanco de Dados SQL do Azure nãoAzure Synapse Analytics (SQL DW) nãoParallel Data Warehouse APPLIES TO: yesSQL Server noAzure SQL Database noAzure Synapse Analytics (SQL DW) noParallel Data Warehouse

A API OpenSqlFilestream obtém um identificador de arquivo compatível com Win32 para um objeto binário grande (BLOB) FILESTREAM armazenado no sistema de arquivos.The OpenSqlFilestream API obtains a Win32 compatible file handle for a FILESTREAM binary large object (BLOB) stored in the file system. O identificador pode ser passado para qualquer uma das seguintes APIs do Win32: ReadFile, WriteFile, TransmitFile, SetFilePointer, SetEndOfFile ou FlushFileBuffers.The handle can be passed to any of the following Win32 APIs: ReadFile, WriteFile, TransmitFile, SetFilePointer, SetEndOfFile, or FlushFileBuffers. Se você passar esse identificador para qualquer outra API do Win32, o erro ERROR_ACCESS_DENIED será retornado.If you pass this handle to any other Win32 API, the error ERROR_ACCESS_DENIED is returned. O identificador deve ser fechado passando-o para a API CloseHandle do Win32 antes de a transação ser confirmada ou revertida.The handle must be closed by passing it to the Win32 CloseHandle API before the transaction is committed or rolled back. O não fechamento do identificador provocará vazamentos de recursos do servidor.Failing to close the handle will cause server-side resource leaks.

Você deve executar todo o acesso ao contêiner de dados FILESTREAM em uma transação do SQL ServerSQL Server .You must perform All FILESTREAM data container access in a SQL ServerSQL Server transaction. Transact-SQLTransact-SQL instruções também podem ser executadas na mesma transação.statements can also be executed in the same transaction. Isso mantém consistência entre os dados do SQL e dados do BLOB do FILESTREAM.This maintains consistency between the SQL data and FILESTREAM BLOB data.

Para acessar o BLOB FILESTREAM usando o Win32, a Autorização do Windows deve estar habilitada.To access the FILESTREAM BLOB by using Win32, Windows Authorization must be enabled.

Importante

Quando o arquivo é aberto para acesso de gravação, a transação pertence ao agente de FILESTREAM.When the file is opened for write access, the transaction is owned by the FILESTREAM agent. Somente a E/S do arquivo do Win32 é permitida até que a transação seja liberada.Only Win32 file I/O is allowed until the transaction is released. Para liberar a transação, o identificador de gravação deve ser fechado.To release the transaction, the write handle must be closed.

SintaxeSyntax

  
HANDLE OpenSqlFilestream (  
    LPCWSTR FilestreamPath,  
    SQL_FILESTREAM_DESIRED_ACCESS DesiredAccess,  
    ULONG OpenOptions,  
    LPBYTE FilestreamTransactionContext,  
    SIZE_T FilestreamTransactionContextLength,  
    PLARGE_INTEGER AllocationSize);  

ParâmetrosParameters

FilestreamPathFilestreamPath
[in] É o caminho nvarchar(max) retornado pela função PathName .[in] Is the nvarchar(max) path that is returned by the PathName function. PathName deve ser chamado a partir do contexto de uma conta que tenha as permissões SELECT ou UPDATE do SQL ServerSQL Server na tabela e na coluna FILESTREAM.PathName must be called from the context of an account that has SQL ServerSQL Server SELECT or UPDATE permissions on the FILESTREAM table and column.

DesiredAccessDesiredAccess
[in] Define o modo usado para acessar dados BLOB do FILESTREAM.[in] Sets the mode used to access FILESTREAM BLOB data. Esse valor é passado para a Função DeviceIoControl.This value is passed to the DeviceIoControl Function.

NomeName ValorValue SignificadoMeaning
SQL_FILESTREAM_READSQL_FILESTREAM_READ 00 Os dados podem ser lidos no arquivo.Data can be read from the file.
SQL_FILESTREAM_WRITESQL_FILESTREAM_WRITE 11 Os dados podem ser gravados no arquivo.Data can be written to the file.
SQL_FILESTREAM_READWRITESQL_FILESTREAM_READWRITE 22 Os dados podem ser lidos e gravados no arquivo.Data can be read and written from the file.

Observação

Esses valores são definidos na enumeração SQL_FILESTREAM_DESIRED_ACCESS em sqlncli.h.These values are defined in the SQL_FILESTREAM_DESIRED_ACCESS enumeration in sqlncli.h.

OpenOptionsOpenOptions
[in] Os atributos e sinalizadores do arquivo.[in] The file attributes and flags. Esse parâmetro também pode incluir qualquer combinação dos sinalizadores a seguir.This parameter can also include any combination of the following flags.

SinalizadorFlag ValorValue SignificadoMeaning
SQL_FILESTREAM_OPEN_NONESQL_FILESTREAM_OPEN_NONE 0x00000000:0x00000000: O arquivo está sendo aberto ou criado sem opções especiais.The file is being opened or created with no special options.
SQL_FILESTREAM_OPEN_FLAG_ASYNCSQL_FILESTREAM_OPEN_FLAG_ASYNC 0x00000001L0x00000001L O arquivo está sendo aberto ou criado para E/S assíncrona.The file is being opened or created for asynchronous I/O.
SQL_FILESTREAM_OPEN_FLAG_NO_BUFFERINGSQL_FILESTREAM_OPEN_FLAG_NO_BUFFERING 0x00000002L0x00000002L O sistema abre o arquivo sem usar cache do sistema.The system opens the file by using no system caching.
SQL_FILESTREAM_OPEN_FLAG_NO_WRITE_THROUGHSQL_FILESTREAM_OPEN_FLAG_NO_WRITE_THROUGH 0x00000004L0x00000004L O sistema não grava por meio de um cache intermediário.The system does not write through an intermediate cache. Ele grava direto no disco.Writes go directly to disk.
SQL_FILESTREAM_OPEN_FLAG_SEQUENTIAL_SCANSQL_FILESTREAM_OPEN_FLAG_SEQUENTIAL_SCAN 0x00000008L0x00000008L Um arquivo é acessado sequencialmente do princípio ao fim.A file is accessed sequentially from beginning to end. O sistema pode usar isso como uma dica para otimizar o cache de arquivo.The system can use this as a hint to optimize file caching. Se um aplicativo mover o ponteiro de arquivo para acesso aleatório, a otimização do cache poderá não ocorrer.If an application moves the file pointer for random access, optimal caching may not occur.
SQL_FILESTREAM_OPEN_FLAG_RANDOM_ACCESSSQL_FILESTREAM_OPEN_FLAG_RANDOM_ACCESS 0x00000010L0x00000010L Um arquivo é acessado aleatoriamente.A file is accessed randomly. O sistema pode usar isso como uma dica para otimizar o cache de arquivo.The system can use this as a hint to optimize file caching.

FilestreamTransactionContextFilestreamTransactionContext
[in] O valor retornado pela função GET_FILESTREAM_TRANSACTION_CONTEXT .[in] The value that is returned by the GET_FILESTREAM_TRANSACTION_CONTEXT function.

FilestreamTransactionContextLengthFilestreamTransactionContextLength
[in] Número de bytes nos dados varbinary(max) retornados pela função GET_FILESTREAM_TRANSACTION_CONTEXT.[in] Number of bytes in the varbinary(max) data that is returned by the GET_FILESTREAM_TRANSACTION_CONTEXT function. A função retorna uma matriz de N bytes.The function returns an array of N bytes. N é determinado pela função e é uma propriedade da matriz do byte retornada.N is determined by the function and is a property of the byte array that is returned.

AllocationSizeAllocationSize
[in] Especifica o tamanho de alocação inicial do arquivo de dados em bytes.[in] Specifies the initial allocation size of the data file in bytes. É ignorado em modo de leitura.It is ignored in read mode. Esse parâmetro pode ser NULL, em cujo caso o comportamento do sistema de arquivos padrão é usado.This parameter can be NULL, in which case the default file system behavior is used.

Valor retornadoReturn Value

Se a função tiver êxito, o valor de retorno será um identificador aberto para um arquivo especificado.If the function succeeds, the return value is an open handle to a specified file. Se houver falha na função, o valor de retorno será INVALID_HANDLE_VALUE.If the function fails, the return value is INVALID_HANDLE_VALUE. Para obter informações sobre erros estendidos, chame GetLastError().For extended error information, call GetLastError().

ExemplosExamples

Os exemplos a seguir mostram como usar a API OpenSqlFilestream para obter um identificador de Win32.The following examples show you how to use the OpenSqlFilestream API to obtain a Win32 handle.

using System.IO;
using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;

namespace FILESTREAM
{
    class Program
    {
        static void Main(string[] args)
        {
            SqlConnection sqlConnection = new SqlConnection(
                "Integrated Security=true;server=(local)");

            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.Connection = sqlConnection;

            try
            {
                sqlConnection.Open();

                //The first task is to retrieve the file path
                //of the SQL FILESTREAM BLOB that we want to
                //access in the application.

                sqlCommand.CommandText =
                      "SELECT Chart.PathName()"
                    + " FROM Archive.dbo.Records"
                    + " WHERE SerialNumber = 3";

                String filePath = null;

                Object pathObj = sqlCommand.ExecuteScalar();
                if (DBNull.Value != pathObj)
                    filePath = (string)pathObj;
                else
                {
                    throw new System.Exception(
                        "Chart.PathName() failed"
                      + " to read the path name "
                      + " for the Chart column.");
                }

                //The next task is to obtain a transaction
                //context. All FILESTREAM BLOB operations
                //occur within a transaction context to
                //maintain data consistency.

                //All SQL FILESTREAM BLOB access must occur in 
                //a transaction. MARS-enabled connections
                //have specific rules for batch scoped transactions,
                //which the Transact-SQL BEGIN TRANSACTION statement
                //violates. To avoid this issue, client applications 
                //should use appropriate API facilities for transaction management, 
                //management, such as the SqlTransaction class.

                SqlTransaction transaction = sqlConnection.BeginTransaction("mainTranaction");
                sqlCommand.Transaction = transaction;

                sqlCommand.CommandText =
                    "SELECT GET_FILESTREAM_TRANSACTION_CONTEXT()";

                Object obj = sqlCommand.ExecuteScalar();
                byte[] txContext = (byte[])obj;

                //The next step is to obtain a handle that
                //can be passed to the Win32 FILE APIs.

                SqlFileStream sqlFileStream = new SqlFileStream(filePath, txContext, FileAccess.ReadWrite);

                byte[] buffer = new byte[512];

                int numBytes = 0;

                //Write the string, "EKG data." to the FILESTREAM BLOB.
                //In your application this string would be replaced with
                //the binary data that you want to write.

                string someData = "EKG data.";
                Encoding unicode = Encoding.GetEncoding(0);

                sqlFileStream.Write(unicode.GetBytes(someData.ToCharArray()),
                    0,
                    someData.Length);

                //Read the data from the FILESTREAM
                //BLOB.

                sqlFileStream.Seek(0L, SeekOrigin.Begin);

                numBytes = sqlFileStream.Read(buffer, 0, buffer.Length);

                string readData = unicode.GetString(buffer);

                if (numBytes != 0)
                    Console.WriteLine(readData);

                //Because reading and writing are finished, FILESTREAM 
                //must be closed. This closes the c# FileStream class, 
                //but does not necessarily close the underlying 
                //FILESTREAM handle. 
                sqlFileStream.Close();

                //The final step is to commit or roll back the read and write
                //operations that were performed on the FILESTREAM BLOB.

                sqlCommand.Transaction.Commit();
            }
            catch (System.Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
            finally
            {
                sqlConnection.Close();
            }
            return;
        }
    }
}
Imports System.IO
Imports System 
Imports System.Collections.Generic 
Imports System.Text 
Imports System.Data 
Imports System.Data.SqlClient 
Imports System.Data.SqlTypes 

Module Module1
    Public Sub Main(ByVal args As String())
        '        Dim sqlConnection As New SqlConnection("Integrated Security=true;server=(local)")
        Dim sqlConnection As New SqlConnection("Integrated Security=true;server=kellyreyue\MSSQL1")

        Dim sqlCommand As New SqlCommand()
        sqlCommand.Connection = sqlConnection

        Try
            sqlConnection.Open()

            'The first task is to retrieve the file path 
            'of the SQL FILESTREAM BLOB that we want to 
            'access in the application. 

            sqlCommand.CommandText = "SELECT Chart.PathName()" + " FROM Archive.dbo.Records" + " WHERE SerialNumber = 3"

            Dim filePath As String = Nothing

            Dim pathObj As Object = sqlCommand.ExecuteScalar()
            If Not pathObj.Equals(DBNull.Value) Then
                filePath = DirectCast(pathObj, String)
            Else
                Throw New System.Exception("Chart.PathName() failed" + " to read the path name " + " for the Chart column.")
            End If

            'The next task is to obtain a transaction 
            'context. All FILESTREAM BLOB operations 
            'occur within a transaction context to 
            'maintain data consistency. 

            'All SQL FILESTREAM BLOB access must occur in 
            'a transaction. MARS-enabled connections 
            'have specific rules for batch scoped transactions, 
            'which the Transact-SQL BEGIN TRANSACTION statement 
            'violates. To avoid this issue, client applications 
            'should use appropriate API facilities for transaction management, 
            'management, such as the SqlTransaction class. 

            Dim transaction As SqlTransaction = sqlConnection.BeginTransaction("mainTranaction")
            sqlCommand.Transaction = transaction

            sqlCommand.CommandText = "SELECT GET_FILESTREAM_TRANSACTION_CONTEXT()"

            Dim obj As Object = sqlCommand.ExecuteScalar()
            Dim txContext As Byte() = Nothing

            Dim contextLength As UInteger

            If Not obj.Equals(DBNull.Value) Then
                txContext = DirectCast(obj, Byte())
                contextLength = txContext.Length()
            Else
                Dim message As String = "GET_FILESTREAM_TRANSACTION_CONTEXT() failed"
                Throw New System.Exception(message)
            End If

            'The next step is to obtain a handle that 
            'can be passed to the Win32 FILE APIs. 

            Dim sqlFileStream As New SqlFileStream(filePath, txContext, FileAccess.ReadWrite)

            Dim buffer As Byte() = New Byte(511) {}

            Dim numBytes As Integer = 0

            'Write the string, "EKG data." to the FILESTREAM BLOB. 
            'In your application this string would be replaced with 
            'the binary data that you want to write. 

            Dim someData As String = "EKG data."
            Dim unicode As Encoding = Encoding.GetEncoding(0)

            sqlFileStream.Write(unicode.GetBytes(someData.ToCharArray()), 0, someData.Length)

            'Read the data from the FILESTREAM 
            'BLOB. 

            sqlFileStream.Seek(0, SeekOrigin.Begin)

            numBytes = sqlFileStream.Read(buffer, 0, buffer.Length)

            Dim readData As String = unicode.GetString(buffer)

            If numBytes <> 0 Then
                Console.WriteLine(readData)
            End If

            'Because reading and writing are finished, FILESTREAM 
            'must be closed. This closes the c# FileStream class, 
            'but does not necessarily close the underlying 
            'FILESTREAM handle. 
            sqlFileStream.Close()

            'The final step is to commit or roll back the read and write 
            'operations that were performed on the FILESTREAM BLOB. 

            sqlCommand.Transaction.Commit()
        Catch ex As System.Exception
            Console.WriteLine(ex.ToString())
        Finally
            sqlConnection.Close()
        End Try
        Return
    End Sub
End Module
#include <windows.h>
#include <sql.h>
#include<sqltypes.h>
#include<sqlext.h>
#include <stdio.h>
#include <sqlncli.h>

#define COPYBUFFERSIZE 4096

/// <summary>
///This class iterates though the ODBC error queue and prints all of the
///accumulated error messages to the console.
/// </summary>

class ODBCErrors
{
private:
    int         m_iLine;    //Source code line on which the error occurred
    SQLSMALLINT m_type;     //Type of handle on which the error occurred
    SQLHANDLE   m_handle;   //ODBC handle on which the error occurred

public:
    /// <summary>
    ///Default constructor for the ODBCErrors class
    ///</summary>

    ODBCErrors()
    {
        m_iLine  = -1;
        m_type   = 0;
        m_handle = SQL_NULL_HANDLE;
    }

    /// <summary>
    ///Constructor for the ODBCErrors class
    /// </summary>
    /// <param name="iLine">
    /// This parameter is the source code line
    /// at which the error occurred.
    ///</param>
    /// <param name="type">
    /// This parameter is the type of ODBC handle passed in
    /// the next parameter.
    ///</param>
    /// <param name="handle">
    /// This parameter is the handle on which the error occurred.
    ///</param>

    ODBCErrors(int iLine, SQLSMALLINT type, SQLHANDLE handle)
    {
        m_iLine  = iLine;
        m_type   = type;
        m_handle = handle;
    }

    ///<summary>
    /// This method iterates though the error stack for the handle passed
    /// into the constructor and displays those errors on the console.
    ///</summary>

    void Print()
    {
        SQLSMALLINT i = 0, len = 0;
        SQLINTEGER  native;
        SQLTCHAR    state[9], text[256];
        SQLRETURN   sqlReturn = SQL_SUCCESS;

        if ( m_handle == SQL_NULL_HANDLE )
        {
            wprintf_s(TEXT("The error handle is not a valid handle.\n"), m_iLine);
            return;
        }

        wprintf_s(TEXT("Error Line(%d)\n"), m_iLine);

        while( sqlReturn == SQL_SUCCESS )
        {
            len = 0;

            sqlReturn = SQLGetDiagRec(
                m_type,
                m_handle,
                ++i,
                state,
                &native,
                text,
                sizeof(text)/sizeof(SQLTCHAR),
                &len);

            if ( SQL_SUCCEEDED(sqlReturn) )
                wprintf_s(TEXT("Error(%d, %ld, %s) : %s\n"), i, native, state, text);
        }
    }
};


BOOL CopyFileToSQL(LPTSTR srcFilePath, LPTSTR dstFilePath, LPBYTE transactionToken, SQLINTEGER cbTransactionToken)
{
    BOOL bRetCode = FALSE;

    HANDLE srcHandle = INVALID_HANDLE_VALUE;
    HANDLE dstHandle = INVALID_HANDLE_VALUE;
    BYTE   buffer[COPYBUFFERSIZE] = { 0 };

    TCHAR *szErrMsgSrc   = TEXT("Error opening source file.");
    TCHAR *szErrMsgDst   = TEXT("Error opening destFile file.");
    TCHAR *szErrMsgRead  = TEXT("Error reading source file.");
    TCHAR *szErrMsgWrite = TEXT("Error writing SQL file.");

    try
    {
        if ( (srcHandle = CreateFile(
            srcFilePath,
            GENERIC_READ,
            FILE_SHARE_READ,
            NULL,
            OPEN_EXISTING,
            FILE_FLAG_SEQUENTIAL_SCAN,
            NULL)) == INVALID_HANDLE_VALUE )
            throw szErrMsgSrc;

        if ( (dstHandle =  OpenSqlFilestream(
            dstFilePath,
            Write,
            0,
            transactionToken,
            cbTransactionToken,
            0)) == INVALID_HANDLE_VALUE)
            throw szErrMsgDst;

        DWORD bytesRead = 0;
        DWORD bytesWritten = 0;

        do
        {
            if ( ReadFile(srcHandle, buffer, COPYBUFFERSIZE, &bytesRead, NULL) == 0 )
                throw szErrMsgRead;

            if (bytesRead > 0)
            {
                if ( WriteFile(dstHandle, buffer, bytesRead, &bytesWritten, NULL) == 0 )
                    throw szErrMsgWrite;
            }
        } while (bytesRead > 0);

        bRetCode = TRUE;
    }
    catch( TCHAR *szErrMsg )
    {
        wprintf_s(szErrMsg);
        bRetCode = FALSE;
    }

    if ( srcHandle != INVALID_HANDLE_VALUE )
        CloseHandle(srcHandle);

    if ( dstHandle != INVALID_HANDLE_VALUE )
        CloseHandle(dstHandle);

    return bRetCode;
}

void main()
{
    TCHAR *sqlDBQuery =
       TEXT("INSERT INTO Archive.dbo.Records(Id, SerialNumber, Chart)")
       TEXT(" OUTPUT GET_FILESTREAM_TRANSACTION_CONTEXT(), inserted.Chart.PathName()")
       TEXT("VALUES (newid (), 5, CONVERT(VARBINARY, '**Temp**'))");

    SQLCHAR transactionToken[32];
    
    SQLHANDLE henv = SQL_NULL_HANDLE;
    SQLHANDLE hdbc              = SQL_NULL_HANDLE;
    SQLHANDLE hstmt             = SQL_NULL_HANDLE;

    try
    {
        //These statements Initialize ODBC for the client application and
        //connect to the database.

        if ( SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_ENV, henv);

        if ( SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION,(void*)SQL_OV_ODBC3, NULL) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_ENV, henv);

        if ( SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_ENV, henv);

        //This code assumes that the dataset name "Sql Server FILESTREAM"
        //has been previously created on the client computer system. An
        //ODBC DSN is created with the ODBC Data Source item in
        //the Windows Control Panel.

        if ( SQLConnect(hdbc, TEXT("Sql Server FILESTREAM"),
                SQL_NTS, NULL, 0, NULL, 0) <= 0 )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_DBC, hdbc);

        //FILESTREAM requires that all read and write operations occur
        //within a transaction.
        if ( SQLSetConnectAttr(hdbc,
            SQL_ATTR_AUTOCOMMIT,
            (SQLPOINTER)SQL_AUTOCOMMIT_OFF,
            SQL_IS_UINTEGER) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_DBC, hdbc);

        if ( SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_DBC, hdbc);

        if ( SQLExecDirect(hstmt, sqlDBQuery, SQL_NTS) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_STMT, hstmt);

        //Retrieve the transaction token.
        if ( SQLFetch(hstmt) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_STMT, hstmt);

        SQLINTEGER cbTransactionToken = sizeof(transactionToken);

        if ( SQLGetData(hstmt, 1,
            SQL_C_BINARY,
            transactionToken,
            sizeof(transactionToken),
            &cbTransactionToken) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_STMT, hstmt);

        //Retrieve the file path for the inserted record.

        TCHAR dstFilePath[1024];
        SQLINTEGER cbDstFilePath;

        if ( SQLGetData(hstmt, 2, SQL_C_TCHAR, dstFilePath, sizeof(dstFilePath), &cbDstFilePath) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_STMT, hstmt);

        if ( SQLCloseCursor(hstmt) != SQL_SUCCESS )
            throw new ODBCErrors(__LINE__, SQL_HANDLE_STMT, hstmt);

        SQLUSMALLINT mode = SQL_ROLLBACK;

        if ( CopyFileToSQL(
            TEXT("C:\\Users\\Data\\chart1.jpg"),
            dstFilePath,
            transactionToken,
            cbTransactionToken) == TRUE )
            mode = SQL_COMMIT;

        SQLTransact(henv, hdbc, mode);
    }
    catch(ODBCErrors *pErrors)
    {
        pErrors->Print();
        delete pErrors;
    }

    if ( hstmt != SQL_NULL_HANDLE )
        SQLFreeHandle(SQL_HANDLE_STMT, hstmt);

    if ( hdbc != SQL_NULL_HANDLE )
        SQLDisconnect(hdbc);

    if ( hdbc != SQL_NULL_HANDLE )
        SQLFreeHandle(SQL_HANDLE_DBC, hdbc); 

    if ( henv != SQL_NULL_HANDLE )
        SQLFreeHandle(SQL_HANDLE_ENV, henv);
}

RemarksRemarks

O SQL ServerSQL Server Native Client deve ser instalado para usar essa API.The SQL ServerSQL Server Native Client must be installed to use this API. O SQL ServerSQL Server Native Client é instalado com ferramentas de cliente do SQL ServerSQL Server ou do SQL ServerSQL Server .The SQL ServerSQL Server Native Client is installed with SQL ServerSQL Server or SQL ServerSQL Server client tools. Para obter mais informações, consulte Instalando o SQL Server Native Client.For more information, see Installing SQL Server Native Client.

Consulte TambémSee Also

Objeto binário grande (Blob) Dados (SQL Server) Binary Large Object (Blob) Data (SQL Server)
Fazer atualizações parciais em dados do FILESTREAM Make Partial Updates to FILESTREAM Data
Evitar conflitos com operações de banco de dados em aplicativos de FILESTREAMAvoid Conflicts with Database Operations in FILESTREAM Applications