SingleTableDiscriminatorFormulaTest.java

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.userguide.inheritance;

import java.math.BigDecimal;
import java.util.List;
import javax.persistence.DiscriminatorValue;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.InheritanceType;

import org.hibernate.annotations.DiscriminatorFormula;
import org.hibernate.dialect.PostgreSQL81Dialect;
import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;

import org.hibernate.testing.RequiresDialect;
import org.junit.Assert;
import org.junit.Test;

import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;

/**
 * @author Vlad Mihalcea
 */
public class SingleTableDiscriminatorFormulaTest extends BaseEntityManagerFunctionalTestCase {

	@Override
	protected Class<?>[] getAnnotatedClasses() {
		return new Class<?>[] {
				DebitAccount.class,
				CreditAccount.class,
		};
	}

	@Test
	@RequiresDialect({PostgreSQL81Dialect.class})
	public void test() {
		doInJPA( this::entityManagerFactory, entityManager -> {
			DebitAccount debitAccount = new DebitAccount( "123-debit" );
			debitAccount.setId( 1L );
			debitAccount.setOwner( "John Doe" );
			debitAccount.setBalance( BigDecimal.valueOf( 100 ) );
			debitAccount.setInterestRate( BigDecimal.valueOf( 1.5d ) );
			debitAccount.setOverdraftFee( BigDecimal.valueOf( 25 ) );

			CreditAccount creditAccount = new CreditAccount( "456-credit" );
			creditAccount.setId( 2L );
			creditAccount.setOwner( "John Doe" );
			creditAccount.setBalance( BigDecimal.valueOf( 1000 ) );
			creditAccount.setInterestRate( BigDecimal.valueOf( 1.9d ) );
			creditAccount.setCreditLimit( BigDecimal.valueOf( 5000 ) );

			entityManager.persist( debitAccount );
			entityManager.persist( creditAccount );
		} );

		doInJPA( this::entityManagerFactory, entityManager -> {
			List<Account> accounts =
					entityManager.createQuery( "select a from Account a" ).getResultList();
			Assert.assertEquals( 2, accounts.size() );
		} );
	}

	//tag::entity-inheritance-single-table-discriminator-formula-example[]
	@Entity(name = "Account")
	@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
	@DiscriminatorFormula(
		"case when debitKey is not null " +
		"then 'Debit' " +
		"else ( " +
		"   case when creditKey is not null " +
		"   then 'Credit' " +
		"   else 'Unknown' " +
		"   end ) " +
		"end "
	)
	public static class Account {

		@Id
		private Long id;

		private String owner;

		private BigDecimal balance;

		private BigDecimal interestRate;

		public Long getId() {
			return id;
		}

		public void setId(Long id) {
			this.id = id;
		}

		public String getOwner() {
			return owner;
		}

		public void setOwner(String owner) {
			this.owner = owner;
		}

		public BigDecimal getBalance() {
			return balance;
		}

		public void setBalance(BigDecimal balance) {
			this.balance = balance;
		}

		public BigDecimal getInterestRate() {
			return interestRate;
		}

		public void setInterestRate(BigDecimal interestRate) {
			this.interestRate = interestRate;
		}
	}

	@Entity(name = "DebitAccount")
	@DiscriminatorValue(value = "Debit")
	public static class DebitAccount extends Account {

		private String debitKey;

		private BigDecimal overdraftFee;

		private DebitAccount() {
		}

		public DebitAccount(String debitKey) {
			this.debitKey = debitKey;
		}

		public String getDebitKey() {
			return debitKey;
		}

		public BigDecimal getOverdraftFee() {
			return overdraftFee;
		}

		public void setOverdraftFee(BigDecimal overdraftFee) {
			this.overdraftFee = overdraftFee;
		}
	}

	@Entity(name = "CreditAccount")
	@DiscriminatorValue(value = "Credit")
	public static class CreditAccount extends Account {

		private String creditKey;

		private BigDecimal creditLimit;

		private CreditAccount() {
		}

		public CreditAccount(String creditKey) {
			this.creditKey = creditKey;
		}

		public String getCreditKey() {
			return creditKey;
		}

		public BigDecimal getCreditLimit() {
			return creditLimit;
		}

		public void setCreditLimit(BigDecimal creditLimit) {
			this.creditLimit = creditLimit;
		}
	}
	//end::entity-inheritance-single-table-discriminator-formula-example[]
}