CODEWITHSUNDEEP
hibernatespring-bootspring-boot-jpa
jalil
jalil

Reputation: 505

Parameter value [....] did not match expected type [java.util.Collection (n/a)]

I am using spring-boot, spring-data-JPA and Hibernate and I've a Form Entity and a Group Entity and they have a @ManyToMany relationship between them.

@ManyToMany(fetch=FetchType.LAZY)
    @JoinTable(name = "form_group",
        joinColumns = @JoinColumn( name = "form_id", referencedColumnName = "id"), 
        inverseJoinColumns = @JoinColumn(name = "group_id", referencedColumnName = "id"))
    @JsonIgnore
    private Collection<Group> groups;

In FormRepository class I have a method called public List<Form> findByGroups(Collection<Group> userGroups); which takes a parameter of type Collection<Group> and is expected to return all the forms which belong to at least one of the groups passed as the method parameter. Here is the Query: 

@Query("SELECT new com.nsia.model.Form(f.id, f.name, f.description, f.createdAt, f.groups, COUNT(i.id)) from Form f LEFT JOIN f.instances i WHERE f.groups IN (?1) group by f.id")

As you can see the userGroups is of type Collection<Group> and inside the Form Entity it is of the same type. When the method findByGroupis called, it throws java.lang.IllegalArgumentException and here is the full message:

java.lang.IllegalArgumentException: Parameter value [Group {id=4, name='DATA_ENTRY_GROUP', description='DATA ENTRY GROUP'}] did not match expected type [java.util.Collection (n/a)]

I'm sure that userGroups is of type Collection<Group> because here is how i'm getting it inside the FormServiceImpl class:

        Collection<Group> groups = userService.getLoggedInUser().getGroups();
        formsList = formRepository.findByGroups(groups);

There are lots of similar questions in StackOverflow and I've tried every one of them and none worked for me, any help will be highly appreciated. THANKS

Upvotes: 5

Views: 12019

Answers (1)

Simon Martinelli
Simon Martinelli

Reputation: 36143

What you are trying is not possible.

The constructor expression cannot take a collection as an argument because the result of the under laying SQL select statement is always a table.

So the only thing you can do is to get a cartesian product back like this where you join f.groups.

@Query("SELECT new com.nsia.model.Form(f.id, f.name, f.description, f.createdAt, g, COUNT(i.id)) from Form f LEFT JOIN f.instances JOIN f.groups g WHERE f.groups IN (?1) group by f.id")

So you will get a record per group but that's probably not what you want.

Upvotes: 1

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