关系的集合。 NoSQL 与 SQL

Question

I understand the difference between NoSQL and SQL, but I still have a small question. It's about a many-to-many relationship. I know that if I need such a relationship, I should use relational databases. However, in my case, I prefer to use document-oriented databases, because I need to store a large number of documents, much larger than the number of entities with relationships.

So, I need to implement user groups. Of course, users can exist outside of groups, therefore they are documents of a separate collection. In addition, one user can be in several groups, which means this is a real many-to-many relationship. People say that “mongo-way” is to make a user with a list of links to groups and a group with a list of links to users, but this option doesn't suit me, because sometimes I need to display a list of groups without displaying a list of the group users, which can take most of the document.

As an alternative, I want to use the traditional “relationship tables” that are used for many-to-many relationships in relational databases.

So my question is, what is the practical difference between using such tables in mysql or in mongodb? As far as I know, there are no foreign keys in mongodb, but does that really prevent me from doing something like this ? I see the problem only in the fact that you can not get rid of the required _id and its indexes. By the way, in this case, should I create indexes for the UserId and GroupId fields?

Or maybe I should give up the idea to fit everything into one database and use SQL and NoSQL together in one project?

Answer 1

below links might help you for schema designing.

https://www.mongodb.com/blog/post/6-rules-of-thumb-for-mongodb-schema-design-part-1