For the mysql utf8 and utf8mb4, and Illegal mix of collations for operation 'like'

Refer to the following posts:

https://www.cnblogs.com/install/p/4417527.html

https://blog.csdn.net/Yetmoon/article/details/79941866

https://www.jb51.net/article/91638.htm

https://blog.csdn.net/u010584271/article/details/80835547

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This last works, the above can be considered to find out

https://blog.csdn.net/qq_26245325/article/details/79157918

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