In this video, I introduced the relational algebra query, which is a different way from the SQL. It has the same procedural query as SQL, but relational algebra will use the symbols to represent the query keyword.
Here is a relational algebra tutorial website.
https://www.guru99.com/relational-algebra-dbms.html
In this video, I want to introduce a relational algebra calculator.
http://clotho.uom.gr/relax/calc.htm#
You could build your own database, and use the relational algebra query to do some practice. And you also could use this relational algebra calculator to evaluate your assignment. It is very helpful to check the correctness.
I use an example to tell you how to use this calculator.
