Lesson $26$: Column alias

In addition to making aliases for tables, you can also make them for columns.

This clears up confusion on which column is which. In the previous exercise, both columns in the result are simply called "name", and that can be confusing.

If you want to use an alias for a column, you add AS after the column name.

If we wanted to use left joins between character names and TV shows and clearly denote which column has character names, and which has TV show names, it would look like this:

SELECT

character.name AS character, tv$\_$show. name AS name

FROM character

LEFT JOIN character$\_$tv$\_$show

ON

character.id $=$ character$\_$tv$\_$show.character$\_$id

LEFT JOIN tv$\_$show

ON character$\_$tv$\_$show.tv$\_$show$\_$id $=$ tv$\_$show.id;

Can you use left joins to match character names with the actors that play them, and use aliases to call the two columns returned character and actor?

Current tables:

character

$\backslash$table$[[$id$,$name$],[1,$Doogie Howser$],[2,$Barney Stinson$],[3,$Lily Aldrin$],[4,$Willow Rosenberg$],[5,$Steve Urkel$],[6,$Homer Simpson$]]$

tv$\_$show

$\backslash$table$[[$id$,$name$],[1,$Buffy the Vampire Slayer$],[2,$How I Met Your Mother$],[3,$Doogie Howser, M$.$D$.],[4,$Friends$]]$

Expected Result:

$\backslash$table$[[$character$,$actor$],[$Doogie Howser,Neil Patrick Harris$],[$Barney Stinson,Neil Patrick Harris$],[$Lily Aldrin,Alyson Hannigan$],[$Willow Rosenberg,Alyson Hannigan$],[$Steve Urkel,null$],[$Homer Simpson,null$]]$

character$\_$tv$\_$show

$\backslash$table$[[$id$,$character$\_$id$,$tv$\_$show$\_$id$],[1,1,3],[2,2,2],[3,3,2],[4,4,1]]$

actor

$\backslash$table$[[$id$,$name$],[1,$Alyson Hannigan$],[2,$Neil Patrick Harris$],[3,$Adam Sandler$],[4,$Steve Carell$]]$

character$\_$actor

$\backslash$table$[[$id$,$character$\_$id$,$actor$\_$id$],[1,1,2],[2,2,2],[3,3,1],[4,4,1]]$