通过多个可选参数过滤 api

Question

I am trying to filter repository method using multiple optional parameters. But I am not getting expected result. Here is my query.

Here visitor entity contains multiple visits and one visits can have one contact person and one timeslot.

Thanks for the help

@Query("select v from Visitor v join v.visits visits join visits.contactPerson cp where "
            + "v.firstName=:firstName or :firstName is NULL or :firstName = '' and "
            + "visits.approvalStatus=:approvalStatus or :approvalStatus is NULL or :approvalStatus = '' "
            + "and cp.firstName=:firstName or :firstName is NULL or :firstName = '' ")
    public List<Visitor> findByFilter(@Param("firstName") String firstName,
            @Param("approvalStatus") String approvalStatus, @Param("firstName") String fName);

Answer 1

You need to add parentheses to make the database understand your query the way you intend:

 + "(v.firstName=:firstName or :firstName is NULL or :firstName = '') and "
 + "(visits.approvalStatus=:approvalStatus or :approvalStatus is NULL or :approvalStatus = '') "
 + "and (cp.firstName=:firstName or :firstName is NULL or :firstName = '')"

The OR operator has a lower precedence than AND so a OR b AND c OR d is parsed as a OR (b AND c) OR d , not as (a OR b) AND (c OR d) .