+ return loadArtistProperties(database.getMultiple(query, artistCreator));
+ }
+
+ /**
+ * Creates a new artist with the given name.
+ *
+ * @param name
+ * The name of the artist
+ * @return The created artist
+ * @throws DatabaseException
+ * if a database error occurs
+ */
+ public Artist createArtist(String name) throws DatabaseException {
+ Query query = new Query(Type.INSERT, "ARTISTS");
+ String id = UUID.randomUUID().toString();
+ query.addValueField(new ValueField("ID", new StringParameter(id)));
+ query.addValueField(new ValueField("NAME", new StringParameter(name)));
+ database.insert(query);
+ return loadArtistProperties(getArtistById(id));
+ }
+
+ /**
+ * Saves the given artist.
+ *
+ * @param artist
+ * The artist to save
+ * @throws DatabaseException
+ * if a database error occurs
+ */
+ public void saveArtist(Artist artist) throws DatabaseException {
+ Query query = new Query(Type.UPDATE, "ARTISTS");
+ query.addValueField(new ValueField("NAME", new StringParameter(artist.getName())));
+ query.addWhereClause(new ValueFieldWhereClause(new ValueField("ID", new StringParameter(artist.getId()))));
+ database.update(query);
+ saveArtistProperties(artist);
+ }
+
+ /**
+ * Saves the properties of the given artist.
+ *
+ * @param artist
+ * The artist whose properties to save
+ * @throws DatabaseException
+ * if a database error occurs
+ */
+ public void saveArtistProperties(Artist artist) throws DatabaseException {
+ saveProperties(artist.getProperties(), "ARTIST_PROPERTIES", "ARTIST", artist.getId());
+ }
+
+ /**
+ * Saves the given properties to the given table for the given principal.
+ *
+ * @param properties
+ * The properties to save
+ * @param table
+ * The table in which to save the properties
+ * @param type
+ * The type of the principal (e. g. “ARTIST” or “TRACK”)
+ * @param id
+ * The ID of the principial
+ * @throws DatabaseException
+ * if a database error occurs
+ */
+ public void saveProperties(Properties properties, String table, String type, String id) throws DatabaseException {
+ if (!properties.isDirty()) {
+ return;
+ }
+ Query query = new Query(Type.DELETE, table);
+ query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(id))));
+ database.update(query);
+ for (Entry<String, String> property : properties) {
+ Query insertQuery = new Query(Type.INSERT, table);
+ insertQuery.addValueField(new ValueField(type, new StringParameter(id)));
+ insertQuery.addValueField(new ValueField("PROPERTY", new StringParameter(property.getKey())));
+ insertQuery.addValueField(new ValueField("VALUE", new StringParameter(property.getValue())));
+ database.insert(insertQuery);
+ }
+ properties.resetDirty();
+ }
+
+ /**
+ * Loads the properties for an artist.
+ *
+ * @param artist
+ * The artist to load the properties for
+ * @return The artist
+ * @throws DatabaseException
+ * if a database error occurs
+ */
+ public Artist loadArtistProperties(final Artist artist) throws DatabaseException {
+ return loadProperties(artist, "ARTIST_PROPERTIES", "ARTIST");
+ }
+
+ /**
+ * Loads the properties of all given artists.
+ *
+ * @param artists
+ * The artists to load the properties for
+ * @return The list of artists
+ * @throws DatabaseException
+ * if a database error occurs
+ */
+ public List<Artist> loadArtistProperties(List<Artist> artists) throws DatabaseException {
+ for (Artist artist : artists) {
+ loadArtistProperties(artist);
+ }
+ return artists;
+ }
+
+ /**
+ * Returns all remix artists involved in the track with the given ID.
+ *
+ * @param trackId
+ * The ID of the track
+ * @return All remix artists involved in the track, in preferred order
+ * @throws DatabaseException
+ * if a database error occurs
+ */
+ public List<Artist> getRemixArtistsByTrack(String trackId) throws DatabaseException {
+ Query query = new Query(Type.SELECT, "ARTISTS");
+ query.addField(new Field("ARTISTS.*"));
+ query.addJoin(new Join(JoinType.INNER, "TRACK_REMIX_ARTISTS", new Field("TRACK_REMIX_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
+ query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_REMIX_ARTISTS.TRACK", new StringParameter(trackId))));
+ query.addOrderField(new OrderField(new Field("TRACK_REMIX_ARTISTS.DISPLAY_ORDER")));