BAEL-3971: Generate DDL script in Spring (#9120)

* BAEL-3971: Generate DDL script in Spring

* BAEL-3971: implement review comments

* BAEL-3971: fix typo

* BAEL-3971: move code examples to module spring-data-jpa-5

Co-authored-by: ashleyfrieze <ashley@incredible.org.uk>

persistence-modules/pom.xml

@@ -61,6 +61,7 @@
         <module>spring-data-jpa-2</module>
         <module>spring-data-jpa-3</module>
         <module>spring-data-jpa-4</module>
+        <module>spring-data-jpa-5</module>
         <module>spring-data-keyvalue</module>
         <module>spring-data-mongodb</module>
         <module>spring-data-neo4j</module>

persistence-modules/spring-data-jpa-5/README.md

@@ -1,4 +1,5 @@
 ### Relevant Articles: 
+
 - [Spring JPA @Embedded and @EmbeddedId](TBD)
 
 ### Eclipse Config 
@@ -9,3 +10,4 @@ This can be ignored:
 - Project -> Properties -> Java Persistance -> JPA -> Error/Warnings -> Select Ignore on "No persistence xml file found in project"
 Or: 
 - Eclipse -> Preferences - Validation - disable the "Build" execution of the JPA Validator 
+

persistence-modules/spring-data-jpa-5/pom.xml

@@ -33,5 +33,5 @@
             <artifactId>h2</artifactId>
         </dependency>
     </dependencies>
-
 </project>
+

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/schemageneration/AccountApplication.java

@@ -0,0 +1,12 @@
+package com.baeldung.schemageneration;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class AccountApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(AccountApplication.class, args);
+    }
+}

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/schemageneration/HibernateUtil.java

@@ -0,0 +1,39 @@
+package com.baeldung.schemageneration;
+
+import com.baeldung.schemageneration.model.Account;
+import com.baeldung.schemageneration.model.AccountSetting;
+import org.hibernate.boot.Metadata;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistry;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.cfg.Environment;
+import org.hibernate.tool.hbm2ddl.SchemaExport;
+import org.hibernate.tool.schema.TargetType;
+
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.Map;
+
+public class HibernateUtil {
+
+    /**
+     * Generates database create commands for the specified entities using Hibernate native API, SchemaExport.
+     * Creation commands are exported into the create.sql file.
+     */
+    public static void generateSchema() {
+        Map<String, String> settings = new HashMap<>();
+        settings.put(Environment.URL, "jdbc:h2:mem:schema");
+
+        StandardServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(settings).build();
+
+        MetadataSources metadataSources = new MetadataSources(serviceRegistry);
+        metadataSources.addAnnotatedClass(Account.class);
+        metadataSources.addAnnotatedClass(AccountSetting.class);
+        Metadata metadata = metadataSources.buildMetadata();
+
+        SchemaExport schemaExport = new SchemaExport();
+        schemaExport.setFormat(true);
+        schemaExport.setOutputFile("create.sql");
+        schemaExport.createOnly(EnumSet.of(TargetType.SCRIPT), metadata);
+    }
+}

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/schemageneration/model/Account.java

@@ -0,0 +1,74 @@
+package com.baeldung.schemageneration.model;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+import java.util.ArrayList;
+import java.util.List;
+
+@Entity
+@Table(name = "accounts")
+public class Account {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @Column(nullable = false, length = 100)
+    private String name;
+
+    @Column(name = "email_address")
+    private String emailAddress;
+
+    @OneToMany(mappedBy = "account", cascade = CascadeType.ALL)
+    private List<AccountSetting> accountSettings = new ArrayList<>();
+
+    public Account() {
+    }
+
+    public Account(String name, String emailAddress) {
+        this.name = name;
+        this.emailAddress = emailAddress;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmailAddress() {
+        return emailAddress;
+    }
+
+    public void setEmailAddress(String emailAddress) {
+        this.emailAddress = emailAddress;
+    }
+
+    public List<AccountSetting> getAccountSettings() {
+        return accountSettings;
+    }
+
+    public void setAccountSettings(List<AccountSetting> accountSettings) {
+        this.accountSettings = accountSettings;
+    }
+
+    public void addAccountSetting(AccountSetting setting) {
+        this.accountSettings.add(setting);
+        setting.setAccount(this);
+    }
+}

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/schemageneration/model/AccountSetting.java

@@ -0,0 +1,68 @@
+package com.baeldung.schemageneration.model;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "account_settings")
+public class AccountSetting {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @Column(name = "name", nullable = false)
+    private String settingName;
+
+    @Column(name = "value", nullable = false)
+    private String settingValue;
+
+    @ManyToOne()
+    @JoinColumn(name ="account_id", nullable = false)
+    private Account account;
+
+    public AccountSetting() {
+    }
+
+    public AccountSetting(String settingName, String settingValue) {
+        this.settingName = settingName;
+        this.settingValue = settingValue;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getSettingName() {
+        return settingName;
+    }
+
+    public void setSettingName(String settingName) {
+        this.settingName = settingName;
+    }
+
+    public String getSettingValue() {
+        return settingValue;
+    }
+
+    public void setSettingValue(String settingValue) {
+        this.settingValue = settingValue;
+    }
+
+    public Account getAccount() {
+        return account;
+    }
+
+    public void setAccount(Account account) {
+        this.account = account;
+    }
+}

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/schemageneration/repository/AccountRepository.java

@@ -0,0 +1,8 @@
+package com.baeldung.schemageneration.repository;
+
+import com.baeldung.schemageneration.model.Account;
+import org.springframework.data.repository.CrudRepository;
+
+public interface AccountRepository extends CrudRepository<Account, Long> {
+    Account findByName(String name);
+}

persistence-modules/spring-data-jpa-5/src/main/java/com/baeldung/schemageneration/repository/AccountSettingRepository.java

@@ -0,0 +1,8 @@
+package com.baeldung.schemageneration.repository;
+
+import com.baeldung.schemageneration.model.AccountSetting;
+import org.springframework.data.repository.CrudRepository;
+
+public interface AccountSettingRepository extends CrudRepository<AccountSetting, Long> {
+    AccountSetting findByAccountId(Long accountId);
+}

persistence-modules/spring-data-jpa-5/src/main/resources/application.properties

@@ -1,2 +1,13 @@
+
+spring.datasource.url=jdbc:h2:mem:baeldung
+
+# JPA-Schema-Generation
+# Use below configuration to generate database schema create commands based on the entity models
+# and export them into the create.sql file
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=create.sql
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-source=metadata
+#spring.jpa.properties.hibernate.format_sql=true
+
 spring.jpa.show-sql=true
 

persistence-modules/spring-data-jpa-5/src/test/java/com/baeldung/schemageneration/AccountRepositoryIntegrationTest.java

@@ -0,0 +1,72 @@
+package com.baeldung.schemageneration;
+
+import com.baeldung.schemageneration.model.Account;
+import com.baeldung.schemageneration.model.AccountSetting;
+import com.baeldung.schemageneration.repository.AccountRepository;
+import com.baeldung.schemageneration.repository.AccountSettingRepository;
+import org.junit.After;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = AccountApplication.class)
+public class AccountRepositoryIntegrationTest {
+
+    private static final String USER_NAME = "Eduard";
+    private static final String USER_EMAIL_ADDRESS = "eduard@gmx.com";
+    private static final String ACCOUNT_SETTING_NAME = "Timezone";
+    private static final String ACCOUNT_SETTING_VALUE = "UTC+02";
+
+    @Autowired
+    private AccountRepository accountRepository;
+
+    @Autowired
+    private AccountSettingRepository accountSettingRepository;
+
+    @After
+    public void tearDown() {
+        accountRepository.deleteAll();
+    }
+
+    @Test
+    public void givenNewAccount_whenSave_thenSuccess() {
+        Account account = new Account(USER_NAME, USER_EMAIL_ADDRESS);
+        accountRepository.save(account);
+
+        assertEquals(1, accountRepository.count());
+    }
+
+    @Test
+    public void givenSavedAccount_whenFindByName_thenFound() {
+        Account account = new Account(USER_NAME, USER_EMAIL_ADDRESS);
+        accountRepository.save(account);
+
+        Account accountFound = accountRepository.findByName(USER_NAME);
+
+        assertNotNull(accountFound);
+        assertEquals(USER_NAME, accountFound.getName());
+        assertEquals(USER_EMAIL_ADDRESS, accountFound.getEmailAddress());
+    }
+
+    @Test
+    public void givenSavedAccount_whenAccountSettingIsAdded_thenPersisted() {
+        Account account = new Account(USER_NAME, USER_EMAIL_ADDRESS);
+        account.addAccountSetting(new AccountSetting(ACCOUNT_SETTING_NAME, ACCOUNT_SETTING_VALUE));
+        accountRepository.save(account);
+
+        Account accountFound = accountRepository.findByName(USER_NAME);
+        assertNotNull(accountFound);
+        AccountSetting accountSetting = accountSettingRepository.findByAccountId(accountFound.getId());
+
+        assertNotNull(accountSetting);
+        assertEquals(ACCOUNT_SETTING_NAME, accountSetting.getSettingName());
+        assertEquals(ACCOUNT_SETTING_VALUE, accountSetting.getSettingValue());
+    }
+
+}

persistence-modules/spring-data-jpa-5/src/test/resources/application-test.properties

@@ -1 +1,3 @@
 spring.jpa.hibernate.ddl-auto=update
+spring.datasource.url=jdbc:h2:mem:baeldung
+