How to use PHP Developer City to implement the function of adding and subtracting shopping cart quantities

How to use PHP Developer City to realize the function of adding and subtracting the number of shopping carts

With the development of e-commerce, shopping websites have become an indispensable part of people's daily lives. The shopping cart is an important part of online shopping. It allows users to temporarily store the items they want to purchase in the shopping cart, making it convenient for users to view and manage their shopping lists. This article will introduce how to use PHP Developer City to implement the function of adding and subtracting shopping cart quantities.

1. Create database table

Before you start writing PHP code, you first need to create a database table to store shopping cart related information. The shopping cart table can contain some basic fields, such as shopping cart ID, user ID, product ID, product name, product price, product quantity, etc. More fields can be added according to actual needs, such as product pictures, product categories, etc.

2. Implement product addition function

One of the basic functions of the shopping cart is to add products to the shopping cart. On the product details page, add an "Add to Cart" button and add a click event for the button. When the user clicks the "Add to Shopping Cart" button, the product-related information (such as product ID, product name, product price, etc.) is transmitted to the background PHP file through POST or GET.

In the background PHP file, you first need to determine whether the user is logged in. If the user is not logged in, Session can be used to temporarily store shopping cart information. If the user is logged in, the shopping cart information can be stored in the database. You can use the INSERT statement to insert product information into the shopping cart table, and set the default product quantity to 1.

3. Implement the shopping cart quantity addition and subtraction function

The shopping cart quantity addition and subtraction function allows users to increase or decrease the quantity of items on the shopping cart page. Generally speaking, you can use the plus and minus buttons to add and subtract quantities. On the shopping cart page, the product information in the user's shopping cart is displayed based on the database query results, and a quantity input box and plus and minus buttons are added for each product.

When the user clicks the plus button, the product ID and increased quantity are sent to the background PHP file through JavaScript or AJAX. In the background PHP file, you first need to determine whether the user is logged in. If the user is not logged in, Session can be used to temporarily store shopping cart information. If the user is logged in, the quantity field of the corresponding product in the shopping cart table can be updated.

When the user clicks the minus button, the product ID and reduced quantity also need to be sent to the background PHP file for processing. In the background PHP file, it is also necessary to determine whether the user is logged in. If the user is not logged in, Session can be used to temporarily store shopping cart information. If the user is logged in, the quantity field of the corresponding product in the shopping cart table can be updated.

4. Implement the shopping cart product deletion function

On the shopping cart page, you can add a "delete" button for each product to allow users to delete an item in the shopping cart. commodity. When the user clicks the "Delete" button, the product ID is sent to the background PHP file for processing through JavaScript or AJAX.

In the background PHP file, it is also necessary to determine whether the user is logged in. If the user is not logged in, Session can be used to temporarily store shopping cart information. If the user is logged in, you can use the DELETE statement to delete the corresponding product record from the shopping cart table.

Summary: Through the above steps, we can use the PHP Developer City to implement the function of adding and subtracting the number of shopping carts. The shopping cart is one of the core functions of an e-commerce website. For users, the function of increasing and decreasing the number of shopping carts is very practical. By properly designing database tables and writing corresponding PHP code, we can easily control and manage the number of shopping carts, improving user experience and functional availability of shopping websites.

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