What should I learn first SQL or NoSQL?

Should I learn SQL or MongoDB first?

Honestly you can do both, if your current role has a need I would certainly address that first. I would suggest learning SQL first and then NoSQL. SQL provides the foundations to understand the concepts of NoSQL. Without SQL you might not understand or find it difficult to understand NoSQL.

Should I learn SQL and NoSQL?

Conclusion. SQL and NoSQL are essential skills for data scientists, analysts, software developers, etc. Thus, if you want to start your career in these fields, learning SQL and NoSQL would be helpful, both in terms of knowledge and paycheck.

What database should I learn first?

Start with an RDBMS system and become proficient in SQL. Those databases still run a lot of the world's data, and they aren't going away any time soon. There's also a lot of documentation and free learning resources out there. I think the easiest place for you to start would be with MySQL or MS SQL Server Express.

Is NoSQL hard to learn if you know SQL?

In short, using NoSQL databases is not difficult. The difficulty comes in using it for the right places in the right way. First of all, it is important to understand that NoSQL doesn't follow the same principles as Relational Databases such as fixed schemas, normalization, support for expressive queries like SQL.