How get two joined tables from database in Spring Jpa?

Question

I have two tables, joined each other. How I can get from database both of them using Spring data jpa?

Code as below,

@Entity
@JsonNaming(PropertyNamingStrategies.UpperSnakeCaseStrategy.class)
public class Employee {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

private String name;
private String phone;
@Enumerated(EnumType.STRING)
private Position position;
private BigDecimal salary;

@OneToOne(mappedBy = "employee", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
private Car car;
}


@Entity
@JsonNaming(PropertyNamingStrategies.UpperSnakeCaseStrategy.class)
public class Car {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

private String model;
private String color;
private double price;

@OneToOne
@JoinColumn(name = "employee_id")
private Employee employee;
}

 // my serice:
@Override
public Employee findEmployeeByName(String name) {
    return employeeRepository.getEmployeeByName(name);
}

result: result

Answer 1

could you please explain what do you want exactly? like If you want just to use both tables in a query that returns a one of your tables (exemple the cars by employee's name) there is no problem. But if you want to return columns from both tables you can have a look at this answer stackoverflow.com/a/47301366/14994239 it shows how to handle this.

Answer 2

As you already had specified fetchType Eager, whenever you fetch any of the object car or the employee you will get all the data of both the corresponding objects.