Consider a table called names that contains last and first names columns, defined as VARCHAR, as listed here:
lname fname ------------ ------------ Ryan Loretta Villegas Arnando Kanieski Carol Brown Alan
Use string concatenation and a space separator to combine first and last names:
SELECT fname ||' '|| lname FROM names ORDER BY lname ;
The result is:
((fname||' ')||lname) --------------------- Alan Brown Carol Kanieski Loretta Ryan Arnando Villegas