Php-PHP price monitoring system design problems

1. an alert is issued whenever the price changes. 2. real-time alert when the user remains on the monitoring page; 3. when the user enters the monitoring page, an alert will be issued for price changes from the last time the user enters the monitoring page to the current period. 4. warning methods include but are not limited to pop-up windows and highlighted colors. The above are the requirements, how to design the database, and how to design the php database

1. Warning is triggered whenever the price changes.
2. Real-time alerts when users remain on the monitoring page;
3. When the user enters the monitoring interface, the user will be notified of price changes from the last time the user enters the monitoring interface to the current time period.
4. Warning methods include but are not limited to pop-up windows and highlighted colors.

The above is the requirement, how to design the database, and how to implement it