How to implement actions in C++ when changing data in a MySQL table?

Question

MySQL

There is a smart home project on the Raspberry Pi, a Java program for Android was written for it, it sends a request to the MySQL table at the touch of a button and changes it, and the C ++ daemon (which will be installed on the Raspberry pi) must poll the table for changes, and when they are detected, it should send signals to the GPIO (Raspberry pi pins), I figured out how to send signals to the GPIO (which will control the relay, etc.), but I did not find information on how to make them send only when the table changes (I was looking for everywhere: StackOverflow and the like)

Answer 1

Use MySQL Connector/C++ to connect to mysql and send queries, do whatever you want based on the responses.

Answer 2

If the Java program is not available for change, then you can try to cheat with a trigger in MySQL, which will write to the add. change log table, which you can then read.

Answer 3

Not exactly an answer to the question, but it seems that a solution through MQTT is more suitable. Everyone who subscribes to a particular topic will be instantly informed about the change. For android, there are already ready-made clients in the market. There are plenty of examples for raspberry - you can implement it in any language.