Should I Always Fully Qualify Column Names In SQL?

Question

Out of interest when working with SQL statements should I always use the fully qualifed column name (tablename.columnname) even if only working with one table e.g.

Answer 1

No.

You should always alias the tables, and you should always qualify your column names with the table aliases.

select
    p.FirstName,
    p.LastName,
    p.SSN
from Person p
where p.ID = 345