Security against select expressions in SQL
===

Considering that you can use a select expression in a query

        select table1.ID, (select table2.salary, table1.id from table2 inner join...
    from table1

and retrieve data that you don't have to reference in the from statement, how is this guarded against as far as security is concerned in enterprise DBMSs?  do table permissions work so that you can not allow any references to them (since this case it isn't in your from statement) 