JPA外键到多个表

Question

We have a table in the database which has the following structure:

referenceId - int foreign key to various tables
tableReference - String defining the table

Is this good design, and is it somehow possible to map this relation?

Answer 1

This is very few information to advise you any solution, but JPA Joined Inheritance works something like that:

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
@DiscriminatorColumn(name="PROJ_TYPE")
@Table(name="PROJECT")
public abstract class Project {
  @Id
  private long id;
  ...
}

@Entity
@DiscriminatorValue("L")
@Table(name="LARGEPROJECT")
public class LargeProject extends Project {
  private BigDecimal budget;
}

@Entity
@DiscriminatorValue("S")
@Table(name="SMALLPROJECT")
  public class SmallProject extends Project {
}

This will manage three tables in DB where the main table PROJECT which contain a column PROJ_TYPE to identify the target table.