أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
Tables that are normalized contain data that has been distributed among the tables, but which may need to be recombined to answer queries from an application. To recombine the data, the programmer will have to use subqueries and/or joins. These SQL structures are more complex to write than a simple SELECT statement.