This snippet is "extension method" for IDataReader.
You can use this snippet below ;
I assume you have datareader like that
SqlDataReader dataReader = command.ExecuteReader();

if (dataReader.IsColumnExists("columnName"))
{
//do something
}


and also you should validation null value control if you work critical datas

if (dataReader.IsColumnExists("columName"))
{
if (dataReader["columName"] != DBNull.Value)
{
//do something
}
}