the universal mysql character set is: utf8_general_ci. Utf8 can only store 3 bytes of characters. While emoticons are usually 4 bytes, you need to use utf8mb4 , such as utf8mb4_general_ci.

if from a program point of view, you need to do mapping at the front end, such as the string [train] can be rendered as? The look on his face. And what you save in mysql is [train] , so that mysql doesn't need to be changed. Many websites do this. After all, utf8mb4 appears late

mysql utf8mb4 Encoding