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