优化扫描

internal/repository/song_repo.go

@@ -95,6 +95,18 @@ func (r *SongRepository) Get(id int) (model.Song, error) {
 	return song, nil
 }
 
+func (r *SongRepository) HasByMediaFileID(mediaFileID int) (bool, error) {
+	var exists int
+	err := r.db.QueryRow("SELECT 1 FROM songs WHERE media_file_id = ? LIMIT 1", mediaFileID).Scan(&exists)
+	if err == sql.ErrNoRows {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
 func (r *SongRepository) Create(title string, artistID, albumID, duration, mediaFileID int) (model.Song, error) {
 	result, err := r.db.Exec(
 		"INSERT INTO songs (title, artist_id, album_id, duration, media_file_id) VALUES (?, ?, ?, ?, ?)",