Php oo - how to do it right?

Question

This is the first time I am creating a website using OO, and I am struggling to find the right path. I don’t like classes where everything runs in the same class, so I separated the entity class and the database class. For example: http://w3cyberlearning.com/php/mysql_oop_product_class.php I believe that this class is not so logical. - why the product should contain a database instance - $ product-> get_products () is absolutely logical, I think.

Therefore, I create a separate class in accordance with the following structure:

Table: Products Fields: productID,productName,categoryID Table: ProductCategory Fields: categoryID,category Classes: Product -productID -productName -category (object) DataProduct -insertProduct($product) insert query... -deleteProduct($product) delete query... -getProduct($id) select data from table ... (join between product and category to get all the fields) $category = new Category($categoryID,$categoryname) $product = new Product($productID,$productName); $product->setCategory($category); return $product; ProductCategory -categoryID -category DataProductCategory ... 

But now I am stuck with some questions, I am dealing with him correctly.

Question 1

To, for example, remove a product, can I execute two different scripts that I have to use?

 http://www.mywebsite.com/books/1/ $id = 1 (1 retrieved from the url) $DataProduct = new DataProduct(); $DataProduct->deleteProduct($id); OR $product = new Product(); $product->setId($id); $DataProduct = new DataProduct(); $DataProduct->deleteProduct($product); 

Question 2

When I retrieve a product from the database, I create a new product object and add the category as an object to the Product. Suppose you have an administrative page where you want to add a new product, and you have a list of options with category identifiers:

 <input type="text" name="productname"> <select name="categories"> <option name="cat1" value="1"> <option name="cat2" value="2"> </select> 

If I want to store this product in a database, what is the best way to do this? In the database, productstable only has the category ID disabled, as a foreign key to the category table.

 $product = new Product(); $product->setProductName("test"); $product->setCategoryID(1); (and add a variable categoryID in the products class) $dataProduct = new DataProduct(); $dataProduct->insertProduct($product); 

and just enter $ product-> categoryID and paste it into the database along with $ product-> productName

or should I do:

 $product = new Product(); $product->setProductName("test"); $dataCategory = new DataCategory(); $dataProduct = new DataProduct(); $category = $dataCategory->getCategory(); (which retrieves the categoryID and name, creates the object and returns it) $product->setCategory($category); $dataProduct->insertProduct($product); 

and save to get the identifier for the category from the object?

Both methods will work, but I'm a little stuck on how to do this.

Answer 1

Question 1

I recommend using the DataProduct approach. Although it is more associated with Product , you are already using DataProduct for simulated activities such as insert and update. I would say that you need to stick to the same object for deletion as well.

Question 2

Although my feeling says that you should stick to the first method, because it is much more accurate, the second is OOP-correct. You only set the properties in the Product class, so it would be dirty if you got a Category ID object in your Product class. Instead, you want to set the entire object.

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OOP is a difficult theoretical question, but you are doing great. I know that it is very difficult to judge your OOP, because often you look at it from the point of view of programming, and the perspective of OOP, which makes it more difficult than it is.