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Databases

Paul Brazell
Paul Brazell
14,371 Points
Posted by Paul Brazell
Paul Brazell
14,371 Points

Group By Genre SQL not returning expected results

I am attempting to do Challenge Task 1 of 2. The question is:

In the library database there's a books table. There are id, title, author, genre and first_published columns. Count all the books in each genre. Include the genre column first and the genre_count as the second column of information.

This is my statement:

SELECT genre, count(genre) as genre_count FROM books GROUP BY genre;

This appears to be returning the expected results, but it is stating incorrect. What am i doing wrong?

3 Answers

Paul Brazell
Paul Brazell
14,371 Points
Paul Brazell
Paul Brazell
14,371 Points

Solved it. Replaced Count(genre) for Count(*)

SELECT genre, count(*) as genre_count FROM books GROUP BY genre;

Alanna Hill
Alanna Hill
5,027 Points
Alanna Hill
Alanna Hill
5,027 Points

Results were the same, I'm still not sure why the original solution was incorrect...

ALBERT QERIMI
ALBERT QERIMI
49,872 Points
ALBERT QERIMI
ALBERT QERIMI
49,872 Points

SELECT * FROM books ORDER By first_published ASC , genre ASC

Paul Brazell
Paul Brazell
14,371 Points
Paul Brazell
Paul Brazell
14,371 Points

The question revolves around a Count() function.

Charlie Harcourt
Charlie Harcourt
8,046 Points
Charlie Harcourt
Charlie Harcourt
8,046 Points

SELECT genre, COUNT(*) AS genre_count FROM books GROUP BY genre;

Just to let you know where I was going wrong was that I was putting genre_count in quotes when they shouldn't have been so that was causing an error for me. :) e.g.

SELECT genre, COUNT(*) AS 'genre_count' FROM books GROUP BY genre;