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Devart.Data.PostgreSql Namespace / PgSqlDataReader Class / IsDBNull Method / IsDBNull(Int32) Method
Example

IsDBNull(Int32) Method
Gets a value indicating whether the column contains non-existent or missing values.
Syntax
'Declaration
 
Public Overloads Overrides Function IsDBNull( _
   ByVal ordinal As Integer _
) As Boolean
 

Parameters

ordinal

Return Value

true if the specified column value is equivalent to System.DBNull; otherwise, false.
Remarks
To avoid raising an error, call this method to check for null column values before calling the typed Get methods (for example, GetByte, GetChar, and so on).
Example
static void GetMyValue(PgSqlConnection myConnection)
{
  PgSqlCommand cmd = new PgSqlCommand("SELECT * FROM Test.AllTypes");
  cmd.Connection = myConnection;
  myConnection.Open();
  try
  {
    PgSqlDataReader reader = cmd.ExecuteReader();
    reader.Read();

    for (short i = 0; i < reader.FieldCount; i++)
    {
      if (reader.IsDBNull(i))
        Console.WriteLine("NULL");
      else
      {
        object someValue = reader.GetValue(i);
        Console.WriteLine(someValue.ToString());
      }
    }

    reader.Close();
  }
  finally
  {
    myConnection.Close();
  }
}
Shared Sub GetMyValue(ByVal myConnection As PgSqlConnection)
  Dim cmd As New PgSqlCommand("SELECT * FROM Test.AllTypes")
  cmd.Connection = myConnection
  myConnection.Open()
  Try
    Dim reader As PgSqlDataReader = cmd.ExecuteReader
    reader.Read()
    For i As Short = 0 To reader.FieldCount - 1
      If reader.IsDBNull(i) Then
        Console.WriteLine("NULL")
      Else
        Console.WriteLine(reader.GetValue(i).ToString)
      End If
    Next i
    reader.Close()
  Finally
    myConnection.Close()
  End Try
End Sub
See Also