* Support write into SQLite by dao.

lib/sqlite/sqlite.class.php

@@ -0,0 +1,53 @@
+<?php
+class sqlite
+{
+    public $app;
+    /**
+     * 全局对象$sqlite
+     * The global sqlite object.
+     *
+     * @var object
+     * @access public
+     */
+    public $dbh = null;
+
+    public function __construct()
+    {
+        global $app;
+        $this->app = $app;
+    }
+
+    /**
+     * 连接sqlite数据库。
+     * Connect to sqlite database.
+     *
+     * @param  string $sqliteFile
+     * @access public
+     * @return object
+     */
+    public function connectSqlite(string $sqliteFile = ''): PDO
+    {
+        $tmpRoot = $this->app->getTmpRoot();
+        if(empty($sqliteFile) || !is_file($sqliteFile)) $sqliteFile = $tmpRoot . 'sqlite.db';
+
+        $sqliteFile = realpath($sqliteFile);
+        if(strpos($sqliteFile, $tmpRoot) !== 0) helper::end("The sqlite file '$sqliteFile' is not in the tmp root '$tmpRoot'");
+
+        $dbh = new PDO("sqlite:$sqliteFile");
+        $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+
+        $this->dbh = $dbh;
+
+        return $dbh;
+    }
+
+    public function exec($sql = '')
+    {
+        $this->dbh->exec($sql);
+    }
+
+    public function processSQL(string $sql): string
+    {
+        return $sql;
+    }
+}