とりあえずPHPのPDOクラスを使ってSQLite3を操作するコード

<?php
	define('ABSPATH', dirname(__FILE__));
	
	function db_connect(){
		$db = new PDO('sqlite:' . ABSPATH . '/sqlite/storetweet.sqlite3');
		return $db;
	}
	
	function db_init(){
		$db = db_connect();
		$db->query('CREATE TABLE user (id INTERGER PRIMARY KEY AUTOINCREMENT, user_id TEXT)');
	}
	
	function db_delete(){
		$db = db_connect();
		$db->query('delete from user_id');
	}
	
	function db_fetch_all(){
		$db = db_connect();
		$res = $db->query('SELECT * FROM user_id');
		while($v = $res->fetch()){
			echo $v[0] . ' : ' . $v[1] . '<br />';
		}		
	}
	
	function db_add_record($user_id){
		$db = db_connect();
		$db->query('insert into user_id (user_id) values ("' . $user_id . '")');
	}