Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Databases Reporting with SQL Aggregate and Numeric Functions Counting Groups

Posted by Caleb Newell
Caleb Newell
12,562 Points

Write a query to count all the unique genres in the books table. Alias it as total_genres.

In the library database there's a books table. There are id, title, author, genre and first_published columns.

Write a query to count all the unique genres in the books table. Alias it as total_genres.

When i put in the query i wrote, it sais, "Your'e query did not preform the correct count."

help is much appreciated :)

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

Please show the query you were entering.

Caleb Newell
Caleb Newell
12,562 Points

Sorry, I don' know why my code did not show up earlier. 

SELECT DISTINCT genre, COUNT(*) AS toatal_genres FROM books;

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

There seems to be a few issues:

  • the instructions only ask for a total count, not a list of genres
  • the "count" needs to be distinct, not the select
  • the alias is set to "toatal_genres" (with an extra "a") instead of "total_genres"
SELECT COUNT(DISTINCT genre) AS total_genres FROM books;