More Than Column Names
The SELECT statements you've seen so far show exactly what's stored in a table. This is useful, but often not useful enough. SQL lets you add to and manipulate these results to make them easier to read or to do “what if” queries. This means you can use strings of characters, mathematical calculations, and functions provided by your system in the SELECT list, with or without column names.
Display Label Conventions
When the results of a query are displayed, each column has a default heading—its name as defined in the database. Column names in databases are often cryptic (so they'll be easy to type) or have no meaning to users unfamiliar with departmental acronyms, nicknames, or project jargon.
You can solve this problem by ...