Which SQL to learn for DS/ML/AI?

Sir,

There are many SQL variants like PostgreSQL, MySQL, Oracale SQL, Microsoft SQL etc…

Which of them is widely used in the Data Science field?
Which of them is suggested to learn for Data Science aspirants?

Can you please suggest Sir.

Thanks in advance.

Hi @Chandra,
One should try to learn the concepts of DBMS primarily. Rest is just q matter of syntax.

Thank you for the reply Sir.
Will work on it!!