Upgrade to some new nextcloud standards

lib/Db/TagMapper.php

@@ -0,0 +1,51 @@
+<?php
+namespace OCA\QuickNotes\Db;
+
+use OCP\IDBConnection;
+use OCP\AppFramework\Db\Mapper;
+
+class TagMapper extends Mapper {
+
+	public function __construct(IDBConnection $db) {
+		parent::__construct($db, 'quicknotes_tags', '\OCA\QuickNotes\Db\Tag');
+	}
+
+	public function find($id, $userId) {
+		$sql = 'SELECT * FROM *PREFIX*quicknotes_tags WHERE id = ? AND user_id = ?';
+		return $this->findEntity($sql, [$id, $userId]);
+	}
+
+	public function findAll($userId) {
+		$sql = 'SELECT * FROM *PREFIX*quicknotes_tags WHERE user_id = ?';
+		return $this->findEntities($sql, [$userId]);
+	}
+
+	public function getTagsForNote($userId, $noteId) {
+		$sql = 'SELECT T.id, T.name FROM *PREFIX*quicknotes_tags T ';
+		$sql.= 'INNER JOIN *PREFIX*quicknotes_note_tags NT ';
+		$sql.= 'ON T.id = NT.tag_id ';
+		$sql.= 'WHERE NT.user_id = ? AND NT.note_id = ?';
+		return $this->findEntities($sql, [$userId, $noteId]);
+	}
+
+	public function getTag($userId, $name) {
+		$sql = 'SELECT * FROM *PREFIX*quicknotes_tags WHERE user_id = ? AND name = ?';
+		return $this->findEntity($sql, [$userId, $name]);
+	}
+
+	public function tagExists($userId, $name) {
+		$sql = 'SELECT * FROM *PREFIX*quicknotes_tags WHERE user_id = ? AND name = ?';
+		try {
+			return $this->findEntities($sql, [$userId, $name]);
+		} catch (DoesNotExistException $e) {
+			return false;
+		}
+		return true;
+	}
+
+	public function dropOld () {
+		$sql = 'DELETE FROM *PREFIX*quicknotes_tags WHERE ';
+		$sql.= 'id NOT IN (SELECT tag_id FROM *PREFIX*quicknotes_note_tags)';
+		return $this->execute($sql, []);
+	}
+}