a tiny crud/rest api in php

crest

<?php
class db
{
	protected static $dbh = false;
	
	public function connect($dsn = null)
	{
		self::$dbh = new PDO($dsn);
		self::$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
	}
	
	protected function fatal_error($exception)
	{
		throw $exception;
		echo "<pre>Error!: $msg\n";
		$bt = debug_backtrace();
		foreach ($bt as $line) {
			$args = var_export($line['args'], true);
			echo "{$line['function']}($args) at {$line['file']}:{$line['line']}\n";
		}
		echo "</pre>";
		die();
	}
}

class table extends db
{
	public function __construct($dsn, $tableName)
	{
		$this->dsn = $dsn;
		$this->tableName = $tableName;
	}

	public function load($id="",$lx=-1,$ly=-1)
	{
		if (!self::$dbh) $this->connect($this->dsn);
		if (strlen($id)) {
			$id = self::$dbh->quote($id);
			$where = "WHERE id=$id";
		} else
			$where = "";
		if ($lx != -1)
			$limit = "LIMIT $lx,$ly";
		else
			$limit = "";
		try {
			$sql = "SELECT * FROM " . $this->tableName . " $where $limit";
			$rows = self::$dbh->query($sql)->fetchall(PDO::FETCH_ASSOC);
		} catch (PDOException $e) {
			$this->fatal_error($e);
		}
		if (strlen($id) && count($rows)) return $rows[0];
		return $rows;
	}
	
	public function save($record)
	{
		if ($record['id'] == null) return false;
		if (!self::$dbh) $this->connect($this->dsn);
		try {
		$columns = array_keys($record);
		$sql = "REPLACE INTO " . $this->tableName . " (" . implode(",", $columns) . ") VALUES (:" . implode(",:", $columns) . ")";
			error_log("sql: $sql");
			$stmt = self::$dbh->prepare($sql);
			foreach ($columns as $column) {
				$params[':'.$column] = $record[$column];
			}
			error_log(var_export($params, true));
			$stmt->execute($params);
		} catch (PDOException $e) {
			$this->fatal_error($e);
			return false;
		}
		return $this->load($record['id']);
	}
}