What does findAll return in JPA?

findAll would yield no results.

Click to see full answer

How does JPA handle null values?

The JPA specification defines that during ordering, NULL values shall be handled in the same way as determined by the SQL standard. The standard specifies that all null values shall be returned before or after all non-null values. It.s up to the database to pick one of the two options.

What is the return datatype of findAll method in?

The returned data types of findAll method are Iterable and List for CrudRepository and JpaRespository.
What does findById return in JPA?
Its findById method retrieves an entity by its id. The return value is Optional&lt.T&gt. . Optional&lt.T&gt. is a container object which may or may not contain a non-null value. If a value is present, isPresent returns true and get returns the value.

Repository – EmployeeRepository. java

Sr.No Method &amp. Description
1 count: long returns the number of entities available.
2 delete(Employee entity): void deletes an entity.
3 deleteAll:void deletes all the entities.
4 deleteAll(Iterable&lt. extends Employee &gt. entities):void deletes the entities passed as argument.