// Deletes all entries that have an outdated timestamp dbmtime. Also cleans up
// entries in Artist and Album table that are not referenced anymore in the
// Track-table.
//
// Returns the number of deleted rows and an error.
func deleteDanglingEntries(db *database.Database) (int64, error) {
r, err := db.Execute("DELETE FROM Track WHERE dbmtime <> ?", db.Mtime())
deletedTracks, _ := r.RowsAffected()
if err != nil {
return deletedTracks, err
}
if _, err := db.Execute("DELETE FROM Album WHERE ID IN " +
"(SELECT Album.ID FROM Album LEFT JOIN Track ON " +
"Album.ID = Track.album_id WHERE Track.album_id " +
"IS NULL);"); err != nil {
return deletedTracks, err
}
if _, err := db.Execute("DELETE FROM Artist WHERE ID IN " +
"(SELECT Artist.ID FROM Artist LEFT JOIN Album ON " +
"Artist.ID = Album.artist_id WHERE Album.artist_id " +
"IS NULL);"); err != nil {
return deletedTracks, err
}
return deletedTracks, nil
}
