You will see the full source code of the demo. You will see how to use:

1. Get Entities List from Database with CrudRepository Interface in Spring Boot MongoDB
2. Find Entity by Primary Key with CrudRepository Interface in Spring Boot MongoDB
3. Create New Entity with CrudRepository Interface in Spring Boot MongoDB
4. Update Entity with CrudRepository Interface in Spring Boot MongoDB
5. Delete Entity with CrudRepository Interface in Spring Boot MongoDB
6. Check Exists Entities with CrudRepository Interface in Spring Boot MongoDB
7. Use Equal Operator in Spring Boot MongoDB
8. Use Not Equal Operator in Spring Boot MongoDB
9. Use Less Than Operator in Spring Boot MongoDB
10. Use Less Than or Equal Operator in Spring Boot MongoDB
11. Use Greater Than Operator in Spring Boot MongoDB
12. Use Greater Than or Equal Operator in Spring Boot MongoDB
13. Use And Clause in Spring Boot MongoDB
14. Use Or Clause in Spring Boot MongoDB
15. Use Like in Spring Boot MongoDB
16. Limit in Spring Boot MongoDB
17. Sort in Spring Boot MongoDB
18. Sort and Limit in Spring Boot MongoDB
19. Sum in Spring Boot MongoDB
20. Count in Spring Boot MongoDB
21. Min and Max in Spring Boot MongoDB
22. Avg in in Spring Boot MongoDB
23. Group By Clause in Spring Boot MongoDB
24. Having Clause in Spring Boot MongoDB

You also see the results after the demo with the illustrations.

You can also copy the code in this app and use it on your project.