How to fetch only the specific child entity along with its Parent entities with specific value using Spring JPA DATA

My Entity classes are below,

Account
    accountId
	balance
	withdrawls
	deposits
    @OneToMany
	List<CustomerAccount> customerAccounts

CustomerAccount
	accountId
	customerId
	accountType
	customerType (Primary/Secondary)
	@OneToOne
	Customer customer

Customer
	accountId
	customerId
	firstName
	lastName

Assume the user searches with
firstName = viki and
lastName = black

AccountRepository

findByCustomerAccountsCustomerFirstNameAndCustomerAccountsCustomerLastame(String firstName, String lastName);

This query returns both the primary and secondary object even when one is getting matched. I dont want to return secondary, when the firstname and lastname matches with Primary. The secondary should be null and Primary should have response.

But it returns both the primary and secondary. Is there a way in spring jpa data to return only
the matched child entity along with the Parent entity??

"CustAccnt":{	
	"Account":{
		"balance":"",
        "deposits":""
	},
	"primary":{
         "firstName":"Viki",
         "lastName":"Black"
	},
	"secondary":{
         "firstName":"Noah",
         "lastName":"Morgan"
	}
}
]}

I think you need a bidirectional link from the CustomerAccount to the Account class and a CustomerAccountRepository class which has a method declared findByCustomerFirstNameAndCustomerLastName that returns the CustomerAccount which links back to an Account.

Why the method you have will not work - Account repository only returns Account objects(unless you add JPQL and map the return object to something else). AccountRepository.findByCustomerAccountsCustomerFirstNameAndCustomerAccountsCustomerLastame
finds you an(/all) Account(/s) that have a CustomerAccount with Customer.firstName and Customer.lastname matching what is provided by the user. The Account still has a one to many relationship to CustomerAccount, so will contain all the CustomerAccounts for the Account(in your case both Viki and Noah).

You need to order by the customer type and use the pagination mechanism. If you really must use the method name convention(I hate it, it's unreadable and every query change requires a restart of the application because of method renaming) the method should probably be findTopByCustomerAccountsCustomerFirstNameAndCustomerAccountsCustomerLastameOrderByCustomerAccountsCustomerTypeAsc

I think the requirement here is to fetch data and process it as well. Some basic processing is possible as part of open projections. However, your expected processing of Primary and Secondary Accounts as in points 2,3 and 4 below will have to be done in a service layer I'm afraid.

1. fetch all accounts,
2. if both primary and secondary customer match, keep both in account,
3. else if primary customer match, remove secondary customer from account,
4. else if secondary customer match, remove primary customer from account.