This is a tricky aspect of SQL and I know that different SQL engines vary on this point, but in general it is better - once you have defined a table alias to use the alias and not the table name. There are cases (not this simple one) where ambiguities result if you don’t follow that advice. Imagine, for example, if you were joining a table to itself. In that case, you would need to be consistent about your references and any reference to the table name would be potentially ambiguous.