GetPgSqlBlob(Int32) Method
Gets the value of the specified column as a
PgSqlBlob object.
'Declaration
Public Overloads Function GetPgSqlBlob( _
ByVal As Integer _
) As PgSqlBlob
Parameters
- i
- The zero-based column ordinal.
Return Value
The value of the specified column as a
PgSqlBlob object.
This example shows how to download a BLOB field from a table using
GetPgSqlBlob method.
public void DownloadBlob(PgSqlConnection pgConnection)
{
PgSqlCommand pgCommand = new PgSqlCommand("SELECT * FROM Test.Pictures", pgConnection);
pgConnection.Open();
PgSqlDataReader pgReader = pgCommand.ExecuteReader(System.Data.CommandBehavior.Default);
try
{
while (pgReader.Read())
{
PgSqlBlob myBlob = pgReader.GetPgSqlBlob(pgReader.GetOrdinal("Picture"));
if(!myBlob.IsNull)
{
string FN = pgReader.GetString(pgReader.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
{
pgReader.Close();
pgConnection.Close();
}
}
Public Sub DownloadBlob(ByVal pgConnection As PgSqlConnection)
Dim pgCommand As New PgSqlCommand("SELECT * FROM Test.Pictures", pgConnection)
pgConnection.Open()
Dim pgReader As PgSqlDataReader = pgCommand.ExecuteReader(System.Data.CommandBehavior.Default)
Try
While pgReader.Read()
Dim myBlob As PgSqlBlob = pgReader.GetPgSqlBlob(pgReader.GetOrdinal("Picture"))
If Not myBlob.IsNull Then
Dim FN As String = pgReader.GetString(pgReader.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
pgReader.Close()
pgConnection.Close()
End Try
End Sub
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