php 数据库操作基础类DBObject Class

php 数据库操作基础类DBObject Class

/* WORKS IN PHP5 ONLY */
 
	class DBObject
	{
		private $id;
		private $id_field;
		private $table_name;
		private $fields = array();
 
		function __construct($table_name, $id_field, $fields)
		{
			$this->table_name = $table_name;
			$this->id_field = $id_field;
 
			foreach($fields as $key)
				$this->fields[$key] = null;
		}
 
		function __get($key)
		{
			return $this->fields[$key];
		}
 
		function __set($key, $value)
		{
			if(array_key_exists($key, $this->fields))
			{
				$this->fields[$key] = $value;
				return true;
			}
			return false;
		}
 
		function select($id)
		{
			global $db;
 
			$db->query("SELECT * FROM " . $this->table_name . " WHERE " . $this->id_field . " = '$id'");
			if(mysql_num_rows($db->result) == 0)
				return false;
			else
			{
				$this->id = $id;
				$row = mysql_fetch_array($db->result, MYSQL_ASSOC);
				foreach($row as $key => $val)
					$this->fields[$key] = $val;
			}
		}
 
		function insert()
		{
			global $db;
 
			unset($this->fields[$this->id_field]);
			$fields = join(", ", array_keys($this->fields));
			$values = "'" . join("', '", $this->fields) . "'";
 
			$db->query("INSERT INTO " . $this->table_name . " ($fields) VALUES ($values)");
 
			$this->id = mysql_insert_id($db->db);
			return $this->id;
		}
 
		function update()
		{
			global $db;
 
			unset($this->fields[$this->id_field]);
			$arrStuff = array();
			foreach($this->fields as $key => $val)
				$arrStuff[] = "$key = '$val'";
			$stuff = implode(", ", $arrStuff);
 
			$db->query("UPDATE " . $this->table_name . " SET $stuff WHERE " . $this->id_field . " = '" . $this->id . "'");
			return mysql_affected_rows($db->db); // Not always correct due to mysql update bug/feature
		}
 
		function delete()
		{
			global $db;
			$db->query("DELETE FROM " . $this->table_name . " WHERE " . $this->id_field . " = '" . $this->id . "'");
			return mysql_affected_rows($db->db);
		}
 
		function empty_table()
		{
			global $db;
			$db->query("DELETE FROM " . $this->table_name);
		}
	}
 
// 
// 	class Person extends DBObject 
// 	{
// 		function __construct()
// 		{
// 			parent::__construct('person', 'person_id', array('name', 'eye_color', 'hair_color'));
// 		}
// 	}
//