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Devart.Data.Universal Namespace / UniDataReader Class / GetUniBlob Method / GetUniBlob(Int32) Method
The zero-based column ordinal.
Example

GetUniBlob(Int32) Method
Gets the value of the specified column as a UniBlob object.
Syntax
'Declaration
 
Public Overloads Function GetUniBlob( _
   ByVal i As Integer _
) As UniBlob
 

Parameters

i
The zero-based column ordinal.

Return Value

The value of the specified column as a UniBlob object.
Example
This example shows how to download a BLOB field from a table using GetUniBlob method.
public void DownloadBlob(UniConnection myConnection)
{
  UniCommand myCommand = new UniCommand("SELECT * FROM Test.Pictures", myConnection);
  myConnection.Open();
  UniDataReader myReader = myCommand.ExecuteReader(System.Data.CommandBehavior.Default);
  try
  {
    while (myReader.Read())
    {
      UniBlob myBlob = myReader.GetUniBlob(myReader.GetOrdinal("Picture"));
      if(!myBlob.IsNull)
      {
        string FN = myReader.GetString(myReader.GetOrdinal("PicName"));
        FileStream fs = new FileStream("D:\\Tmp\\"+FN+".bmp", FileMode.Create);
        BinaryWriter w = new BinaryWriter(fs);
        w.Write(myBlob.Value);
        w.Close();
        fs.Close();
        Console.WriteLine(FN+" downloaded.");
      }
    }
  }
  finally
  {
    myReader.Close();
    myConnection.Close();
  }
}
Public Sub DownloadBlob(ByVal myConnection As UniConnection)
  Dim myCommand As New UniCommand("SELECT * FROM Test.Pictures", myConnection)
  myConnection.Open()
  Dim myReader As UniDataReader = myCommand.ExecuteReader(System.Data.CommandBehavior.Default)
  Try
    While myReader.Read()
      Dim myBlob As UniBlob = myReader.GetUniBlob(myReader.GetOrdinal("Picture"))
      If Not myBlob.IsNull Then
        Dim FN As String = myReader.GetString(myReader.GetOrdinal("PicName"))
        Dim fs As FileStream = New FileStream("D:\Tmp\" + FN + ".bmp", FileMode.Create)
        Dim w As BinaryWriter = New BinaryWriter(fs)
        w.Write(myBlob.Value)
        w.Close()
        fs.Close()
        Console.WriteLine(String.Concat(FN, " downloaded."))
      End If
    End While
  Finally
    myReader.Close()
    myConnection.Close()
  End Try
End Sub
Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also