Select multiple fields using findByField in JPA - spring-boot

Question

I am trying to select mulitple values from a table where input can be any of the 5 columns of the table or a combination of those fields.
In order to use findByField in JPA I have to many combinations of findByField and call them selectively by checking which field is blanks.
Is there an easier solution to this?
I have 5 columns in a table that I would like to query on.
If user enters all 5 then i want to select using all 5 fields like below.
select * from table where field1 = :field1 and field2 = :field2 and field3 = :field3 and field4 = :field4 and field5 = :field5;
But if user enters only 2 fields, then I just want to query on those 2 fields like this.
select * from table where field3 = :field3 and field5 = :field5.
In JPA we can do findByField1AndField2AndField3
But i am having for 5 different input possibilities i will have to create like 120 possibilities.
So is there any simpler solution?
Thank you!

Answer 1

It seems there is no automatic generator to build all possible combinations of JPA queries, but you should use the power of JPA dynamic queries like this :
Build predicates for all the fields and apply them on the basis of user input.
public List<Employee> findByCriteria(String employeeName){
return employeeDAO.findAll(new Specification<Employee>() {
#Override
public Predicate toPredicate(Root<Employee> root, CriteriaQuery<?> query, CriteriaBuilder criteriaBuilder) {
List<Predicate> predicates = new ArrayList<>();
if(employeeName!=null) {
predicates.add(criteriaBuilder.and(criteriaBuilder.equal(root.get("employeeName"), employeeName)));
}
return criteriaBuilder.and(predicates.toArray(new Predicate[predicates.size()]));
}
});
}
Helpful Link: https://javadeveloperzone.com/spring/spring-jpa-dynamic-query-example/

Answer 2

You can use a custom #Query in your #Repository interface and add as many params as you need.
#Query(value="SELECT *
FROM table
WHERE (:field1 IS NULL
OR field1 = :field1)
AND (:field2 IS NULL
OR field2 = :field2)",
nativeQuery=true)
public Table findMatchingTable(#Param("field1") String field1, #Param("field2") String field2)