带有连接和动态参数的 JPA Criteria Builder

Question

I have 2 classes with One-to-Many relationship. Customer (class) has many Transactions (class)

 public class Customer {
     @Id
     private Long clientId;
     private String name;
     @OneToMany
     private List<Transactions> transactions;

}

 public class Transactions {
  @JoinColumn(name = "clientId")
  private Transactions transactions;
  private int statusType;
  private String amount;
}




 int dynamicValue = 1003;
 CriteriaQuery<Customer> criteriaQuery = getBuilder().createQuery(Customer.class);
    Root<Customer> customersRoot = criteriaQuery.from(Customer.class);
    Join<Customer, Transactions> transactions = customersRoot.join("transactions");

    TypedQuery<Customer> query = em.createQuery(criteriaQuery.select(customerRoot).where(getBuilder().equal(transactions.get("statusType"), dynamicValue)));
    List<Customer> customerList = (List<Customer>) query.getResultList();

I have 2 data from the DB: Customer Table

ClientId   | Name         | 
1          | James        |
2          | Eli          | 

Transactions Table:

  ClientId     | Status Type| Amount| TransactionId |
    1          | 1002       | 100   | 1             |
    1          | 1003       | 200   | 2             |

I need to make my query above to accept multiple parameters (dynamic). These parameters will be coming from the Customer's attributes such as name, some parameters will be coming from the Transactions class. However, when I tried to execute my code above it always get the 1st record (1002) in my database which is incorrect.

Please give me somelight. Questions:

1. How can I achieved to have multiple dynamic parameters in criteria builder?
2. What is wrong with my query why it always get the 1st record?

Answer 1

You are currently just passing in a Literal. This is not the same as a Parameter. See http://www.datanucleus.org:15080/products/accessplatform_5_2/jpa/query.html#_criteria_api_parameters

Change your code to

CriteriaQuery<Customer> criteriaQuery = getBuilder().createQuery(Customer.class);
    Root<Customer> customersRoot = criteriaQuery.from(Customer.class);
    Join<Customer, Transactions> transactions = customersRoot.join("transactions");

ParameterExpression param = getBuilder().parameter(int.class, "myParam");
TypedQuery<Customer> query = em.createQuery(criteriaQuery.select(customerRoot).where(getBuilder().equal(transactions.get("statusType"), param)));

// Execute with first parameter value
query.setParameter("myParam", 1003);
List<Customer> customerList = (List<Customer>) query.getResultList();

Then if you get a problem with the result, you look in the JPA providers log at the SQL that was executed, and can understand the problem better