How do I pivot values into columns with SQLite?

Question

I made a table called tbl with this code:

CREATE TABLE tbl
    (
      `Year` int, 
      `Album` varchar(255),
      `Artist` varchar(255),
      `Label` varchar(255),
      `Genre` varchar(255),
      `id` int
    )
;

INSERT INTO tbl
    (
      `Year`,
      `Album`,
      `Artist`,
      `Label`,
      `Genre`,
      `id`
    )
VALUES
    (1990, "Greatest Hits", "The Best", "Least Def", "hip hop", 123),
    (1990, "Greatest Hits", "The Best", "Roofless", "hip hop", 123),
    (1990, "4-Boyz", "3 Guyz", "Pacific", "pop-dance", 23),
    (1990, "4-Boyz", "3 Guyz", "Atlantic", "pop-dance", 23)
;

I want to run a query to show me the count of genres for each year, without double counting because of the Label column. I want this:

Year, hip hop, pop-dance
1990, 1, 1

What query must I run to get what I want?

score 5 · Accepted Answer · answered May 11 '16 at 18:57

5

Because you can't use pivot, you can do this.

select year,
count(distinct case when `Genre` = 'hip hop' then 1 end) as hiphop,
count(distinct case when `Genre` = 'pop-dance' then 1 end) as popdance
from tbl
group by year

answered May 11 '16 at 18:57

Vamsi Prabhala

48,685
4
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58

http://www.sqlfiddle.com/#!5/763ad/3 If they want to mess around with it anymore. – Dresden May 11 '16 at 19:01
2

If I add more rows with more different Genres, is there a way to take those into account without having to add more `count(distinct case when `Genre` = 'new genre' then 1 end) as newgenre` statements? – Username May 11 '16 at 20:47
1

No,unfortunately afaik. You will have to do this manually. If it were SQL Server or Oracle you would have had an option of doing a dynamic pivot. – Vamsi Prabhala May 11 '16 at 20:49
@vkp How about MySQL or PostgreSQL? – Username May 11 '16 at 22:26

score 1 · Answer 2 · edited May 25 '20 at 10:04

The accepted answer worked for me.

I add here a more complex case, with join, in case someone needs.

How do I pivot values into columns with SQLite?

2 Answers2

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