GoScrobble/docs/removing_bad_data.md

Removing bad data

This is by no means recommended.. But during testing I somehow scrobbled movies.

SET FOREIGN_KEY_CHECKS=0;
DELETE FROM artists WHERE `name` = "%!s(<nil>)";
DELETE FROM albums WHERE `name` = "%!s(<nil>)";
DELETE album_artist FROM album_artist LEFT JOIN artists ON artists.uuid = album_artist.artist WHERE artists.uuid is null;
DELETE album_artist FROM album_artist LEFT JOIN albums ON albums.uuid = album_artist.album WHERE albums.uuid is null;
DELETE track_artist FROM track_artist LEFT JOIN artists ON artists.uuid = track_artist.artist WHERE artists.uuid is null;
DELETE tracks FROM tracks LEFT JOIN track_artist ON track_artist.track = tracks.uuid WHERE track_artist.track IS NULL;
DELETE scrobbles FROM scrobbles LEFT JOIN tracks ON tracks.uuid = scrobbles.track WHERE tracks.uuid is null;
SET FOREIGN_KEY_CHECKS=1;

Removing duplicates (based on same song played in same hour)

-- backup stuff first
DROP TABLE BACKUP_scrobbles;
CREATE TABLE BACKUP_scrobbles (primary key (uuid)) as select * from scrobbles;

SELECT BIN_TO_UUID(`user`, true), scrobbles.*, count(*) FROM scrobbles
-- WHERE `user`= UUID_TO_BIN('<userUUID>', true)
GROUP BY track, HOUR(created_at)
HAVING count(*) > 1
ORDER BY COUNT(*) DESC;

-- will only delete one set of dupes at a time, run until 0 updated rows
DELETE scrobbles
FROM scrobbles
WHERE uuid IN ( 
    SELECT uuid FROM (
        SELECT `uuid` FROM scrobbles
        WHERE `user`= UUID_TO_BIN('<userUUID>', true)
        GROUP BY track, HOUR(created_at)
        HAVING count(*) > 1
    ) x
);