Hello all
I'm new to OOP. I'm trying to improve my coding skills & habits as much as possible.

I知 giving you a basic example of a dummy class to manage posts that has methods Save, Delete, Fetch All, fetch by id. I want you to point out any mistakes I知 making, and any code improvements I can make to optimise the way I code.

I知 looking to implement some sort of error catch (which I致e attempted) but need guidance in this area.

Code:
<?php


class Post {

	var $error = NULL;

	
	function Post() {
	
	}


	
	function save($title, $post_date, $content, $categories, $status, $url) {
		if(get_magic_quotes_gpc()) {
			$title = stripslashes($title);
			$contact = stripslashes($contact);
		}
		
		//check required fields aren't empty
		$this->isEmpty($title);
		$this->isEmpty($post_date);
		$this->isEmpty($content);
		
		$name = mysql_real_escape_string($title);
		$email = mysql_real_escape_string($content);
		
		$query = "INSERT INTO ".TBL_POSTS."(title, post_date, content, date_created, status, url) VALUES('$title', '$post_date', '$content', '$date_created', '$status', '$url')";
		$result = mysql_query($query);
		$data = mysql_fetch_object($result);
		
		
	}
	
	
	
	function delete($id) {
		$query = "DELETE FROM ".TBL_POSTS." WHERE id = '$id";
		$result = mysql_query($query);
		if (!$result) {
			$this->error = 1;
		}
	}
	
	
	
	function isEmpty($field) {
		if ($field == NULL or $field == '') {
			$this->error = 1;
		}
	}
	
	
	
	function fetchAll() {
		$query = "SELECT * FROM ".TBL_POSTS;
		$result = mysql_query($query);
		$data = mysql_fetch_array($result);
		if (mysql_num_rows($result) == 0) {
			$this->error = 1;
		} else {
			return $data;
		}
	}
	
	
	
	function fetchAllPosted() {
		$query = "SELECT * FROM ".TBL_POSTS." WHERE post_date <= '$today'";
		$result = mysql_query($query);
		$data = mysql_fetch_array($result);
		if (mysql_num_rows($data) == 0) {
			$this->error = 1;
		} else {
			return $data;
		}
	}
	
	
	
	function get($id) {
		$query = "SELECT * FROM ".TBL_POSTS." WHERE id = '$id";
		$result = mysql_query($query);
		$data = mysql_fetch_array($result);
		if (mysql_num_rows($data) == 0) {
			$this->error = 1;
		} else {
			return $data;
		}
	}
	
	
	function getByUrl($url) {
		$query = "SELECT * FROM ".TBL_POSTS." WHERE url = '$url";
		$result = mysql_query($query);
		$data = mysql_fetch_array($result);
		if (mysql_num_rows($data) == 0) {
			$this->error = 1;
			return false;
		} else {
			return $data;
		}
	}
	
}