When the first field in a row of data is null, you can still retrieve the following data by using the appropriate column index or column name to access the data.

If you are using a DataReader object to retrieve data from a database, you can use the GetValue method to retrieve the value of a specific column in the current row. The GetValue method takes an integer parameter that represents the index of the column, or a string parameter that represents the name of the column.

Here’s an example of how you can retrieve data from a DataReader object when the first field is null:

using (var connection = new SqlConnection(connectionString))
{
    using (var command = new SqlCommand("SELECT col1, col2, col3 FROM MyTable", connection))
    {
        connection.Open();

        using (var reader = command.ExecuteReader())
        {
            while (reader.Read())
            {
                // Accessing data by column index
                string col1 = reader.GetValue(0)?.ToString();
                string col2 = reader.GetValue(1)?.ToString();
                string col3 = reader.GetValue(2)?.ToString();

                // Accessing data by column name
                string col1ByName = reader["col1"]?.ToString();
                string col2ByName = reader["col2"]?.ToString();
                string col3ByName = reader["col3"]?.ToString();

                // Use the retrieved data here
            }
        }
    }
}

In this example, the GetValue method is used to retrieve the values of the columns by their index. The ?.ToString() operator is used to handle cases where the value is null.

Alternatively, you can access the data by column name using the [] operator and providing the name of the column as a string. Again, the ?.ToString() operator is used to handle null values.

Once you have retrieved the data, you can use it as needed in your code.