Create class Database for better access to PDO

With this new class things like transactions are possible for the first time

Backend/Core/Data/Database.php

@@ -0,0 +1,75 @@
+<?php
+
+/**
+ * This class allow a more direct access to all Database
+ * classes for easier access to things like transactions
+ * @since 2.0.0
+ */
+class Database extends PDO
+{
+	private PDOStatement $query;
+
+	/**
+	 * Opens the connection to the DB automatically
+	 *
+	 * @throws PDOException If the connection can't be established
+	 */
+	public function __construct()
+	{
+		parent::__construct('mysql:host=' . DB_HOST . '; dbname=' . DB_NAME, DB_USER, DB_PASS);
+	}
+
+	/**
+	 * Executes an SQL query
+	 *
+	 * @param string $queryStr SQL query as string
+	 * @param array<string,string> $values Escaped values
+	 * @throws PDOException When anything goes wrong
+	 * @return bool Whether the query was executed successfully
+	 */
+	public function execute(string $queryStr, array $values): bool
+	{
+		$this->query = $this->prepare($queryStr);
+
+		if ($this->query !== false)
+			return $this->query->execute($values);
+		return false;
+	}
+
+	/**
+	 * Reads data (row by row) from database
+	 * Access returned value via $return['ColumnName']
+	 *
+	 * @see https://bugs.php.net/bug.php?edit=2&id=44341 Always string values!
+	 * @throws PDOException When anything goes wrong
+	 * @return array<string,string>|null Result as array - null on failure
+	 */
+	public function fetch(): ?array
+	{
+		$this->query->setFetchMode(PDO::FETCH_ASSOC);	// Fetch into array
+		if (($result = $this->query->fetch()) !== false)
+			return $result;
+		return null;
+	}
+
+	/**
+	 * Reads data (all rows) from database
+	 *
+	 * @see https://bugs.php.net/bug.php?edit=2&id=44341 Always string values!
+	 * @return array<array<int|string,string>> Null on error, array with values (as string!) otherwise (PDO::FETCH_ASSOC)
+	 */
+	public function fetchAll(): array
+	{
+		return $this->query->fetchAll(PDO::FETCH_ASSOC);
+	}
+
+	/**
+	 * Counts the effected rows of the last query
+	 *
+	 * @return integer Effected rows
+	 */
+	public function count(): int
+	{
+		return $this->query->rowCount();
+	}
+}