java - Spring data JPA and parameters that can be null

Question

My understanding is, that with Spring data JPA I cannot have a query method to fetch all rows where a column equals a given non-null method parameter and use the same method to fetch all rows where this column is NULL when the method parameter is null.

Is that correct?

So I have to distinguish this in my JAVA code and I must use a separate query method explicitly asking for null values, like in the example below?

// Query methods
List<Something> findByParameter(Parameter parameter);
List<Something> findByParameterIsNull();

...

List<Something> result = new ArrayList<>();

if (parameter == null)
  result = findByParameterIsNull();
else
  result = findByParameter(parameter);

That's bad, if I have 4 parameters which could be null and would have to code 16 different query methods.

question from:https://stackoverflow.com/questions/30219486/spring-data-jpa-and-parameters-that-can-be-null

Answer 1

You are right.

A request has been made to support better handling of null parameters. https://jira.spring.io/browse/DATAJPA-121

In your case, i would advise you to write your repository implementation and to use a custom CriteriaQuery to handle your case.

Also you can use the @Query annotation with the is null syntax :

@Query("[...] where :parameter is null"
public List<Something> getSomethingWithNullParameter();

EDIT

Since Spring data jpa 2.0, spring now supports @Nullable annotation. This can be helpful to handle null parameters passed.

From the documentation :

@Nullable – to be used on a parameter or return value that can be null.