After writing the config file, how can I query it by conditions in the PHP file?

After writing the config file, how can I query the config file by condition in the PHP file? that is, add the product to the shopping cart. I am a beginner, I hope you can write more details.

Reply to discussion (solution)

Are you talking about SQL statements?

SELECT * FROME table WHERE...

Are you talking about SQL statements?

SELECT * FROME table WHERE... No, that is, how can I add him to the shopping cart? the item information is displayed in the shopping cart list.

Are you talking about SQL statements?

SELECT * FROME table WHERE... No, that is, how can I add him to the shopping cart? the item information is displayed in the shopping cart list.

Generally, this is a cookie/session operation, which is stored in the cookie/session.

Example: http://www.jb51.net/article/7053.htm

Are you talking about SQL statements?

SELECT * FROME table WHERE... No, that is, how can I add him to the shopping cart? the item information is displayed in the shopping cart list.

Generally, this is a cookie/session operation, which is stored in the cookie/session.

Example: http://www.jb51.net/article/7053.htm
Do I need to check the database?

Generally, you do not need to insert a database before settlement. you can use cookies/sessions to save temporary data.

Generally, you do not need to insert a database before settlement. you can use cookies/sessions to save temporary data.
It feels complicated.