Transact-SQL, Ms SQL, My SQL

Luckily for me to see your answer to the question on find all numbers that appear at least three times consecutively.

I am a beginner with MySQL. I am trying to solve database problems on leetcode.com. And I have solved all the easy level problems, and would love to go further in this field. I have learned all sql topics on W3SCHOOL, which talks about basic functions, JOINS, and some syntaxes, however that is not enough to master SQL.

When I studied your answer, I found some concepts as Transact_SQL, MS SQL and MySQL. Since I am using MySQL, thus some Transact-SQL functions can't work on my workbench.

Sorry for the messy words above. I mean could you please help go further? May be recommend me some books? Or give me some hints on what should I do next to learn SQL?

Thank you very much and have a nice day.

Best regards,

my email is wei.yuxin7@gmail.com Looking forward to your reply.