The select statement can also include one or more expressions, which allow you to manipulate the data that is retrieved.

select expression [, expression]... 
     from table_list 

An expression is any combination of constants, column names, functions, subqueries, or case expressions, connected by arithmetic or bitwise operators and parentheses. Expressions can include nested items (you can nest up to 32 functions in an expression).

If any table or column name in the list does not conform to the rules for valid identifiers, set the quoted_identifier option on and enclose the identifier in double quotes.