Column IDs range from 0 to ULDataReader.FieldCount-1, inclusively.
Note that in result sets, not all columns have names and not all column names are unique. If you are not using aliases, the
name of a non-computed column is prefixed with the name of the table the column is from. For example, MyTable.ID is the name
of the only column in the result set for the query "SELECT ID FROM MyTable".
Column IDs and counts may change during a schema upgrade. To correctly identify a column, access it by name or refresh the
cached IDs and counts after a schema upgrade.
This method is identical to the ULCursorSchema.GetColumnID method.