BAEL-6004 TRUNCATE table in Spring Data JPA (#13554)

persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/truncate/EntityManagerRepository.java

@@ -0,0 +1,22 @@
+package com.baeldung.spring.data.persistence.truncate;
+
+import org.springframework.stereotype.Repository;
+import org.springframework.transaction.annotation.Transactional;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+
+@Repository
+public class EntityManagerRepository {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Transactional
+    public void truncateTable(String tableName) {
+        String sql = "TRUNCATE TABLE " + tableName;
+        Query query = entityManager.createNativeQuery(sql);
+        query.executeUpdate();
+    }
+}

persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/truncate/JdbcTemplateRepository.java

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+package com.baeldung.spring.data.persistence.truncate;
+
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.stereotype.Repository;
+import org.springframework.transaction.annotation.Transactional;
+
+@Repository
+public class JdbcTemplateRepository {
+    private final JdbcTemplate jdbcTemplate;
+
+    public JdbcTemplateRepository(JdbcTemplate jdbcTemplate) {
+        this.jdbcTemplate = jdbcTemplate;
+    }
+
+    @Transactional
+    public void truncateTable(String tableName) {
+        String sql = "TRUNCATE TABLE " + tableName;
+        jdbcTemplate.execute(sql);
+    }
+}

persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/truncate/MyEntity.java

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+package com.baeldung.spring.data.persistence.truncate;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import java.util.Objects;
+
+@Entity
+@Table(name = MyEntity.TABLE_NAME)
+public class MyEntity {
+
+    public final static String TABLE_NAME = "my_entity";
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        MyEntity myEntity = (MyEntity) o;
+        return Objects.equals(id, myEntity.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+
+    @Override
+    public String toString() {
+        return "MyEntity{" +
+                "id=" + id +
+                '}';
+    }
+}

persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/truncate/MyEntityRepository.java

@@ -0,0 +1,20 @@
+package com.baeldung.spring.data.persistence.truncate;
+
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.stereotype.Repository;
+
+import javax.transaction.Transactional;
+
+@Repository
+public interface MyEntityRepository extends CrudRepository<MyEntity, Long> {
+
+    @Modifying
+    @Transactional
+    // need to wrap in double quotes due to
+    // spring.jpa.properties.hibernate.globally_quoted_identifiers=true backward compatibility
+    // property disabled in tests
+    @Query(value = "truncate table " + MyEntity.TABLE_NAME, nativeQuery = true)
+    void truncateTable();
+}

persistence-modules/spring-data-jpa-repo-2/src/main/java/com/baeldung/spring/data/persistence/truncate/TruncateSpringBootApplication.java

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+package com.baeldung.spring.data.persistence.truncate;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.domain.EntityScan;
+
+@EntityScan(basePackageClasses = MyEntity.class)
+@SpringBootApplication
+public class TruncateSpringBootApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(TruncateSpringBootApplication.class);
+    }
+}

persistence-modules/spring-data-jpa-repo-2/src/test/java/com/baeldung/spring/data/persistence/truncate/TruncateIntegrationTest.java

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+package com.baeldung.spring.data.persistence.truncate;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest(classes = TruncateSpringBootApplication.class,
+        properties = "spring.jpa.properties.hibernate.globally_quoted_identifiers=false")
+class TruncateIntegrationTest {
+
+    @Autowired
+    private MyEntityRepository myEntityRepository;
+
+    @Autowired
+    private JdbcTemplateRepository jdbcTemplateRepository;
+
+    @Autowired
+    private EntityManagerRepository entityManagerRepository;
+
+    @Test
+    void givenSomeData_whenRepositoryTruncateDate_thenNoDataLeft() {
+        int givenCount = 3;
+        givenDummyData(givenCount);
+
+        myEntityRepository.truncateTable();
+
+        assertThat(myEntityRepository.count())
+            .isNotEqualTo(givenCount)
+            .isZero();
+    }
+
+    @Test
+    void givenSomeData_whenEntityManagerTruncateDate_thenNoDataLeft() {
+        int givenCount = 3;
+        givenDummyData(givenCount);
+
+        entityManagerRepository.truncateTable(MyEntity.TABLE_NAME);
+
+        assertThat(myEntityRepository.count())
+            .isNotEqualTo(givenCount)
+            .isZero();
+    }
+
+    @Test
+    void givenSomeData_whenJDBCTemplateTruncateDate_thenNoDataLeft() {
+        int givenCount = 3;
+        givenDummyData(givenCount);
+
+        jdbcTemplateRepository.truncateTable(MyEntity.TABLE_NAME);
+
+        assertThat(myEntityRepository.count())
+            .isNotEqualTo(givenCount)
+            .isZero();
+    }
+
+    private void givenDummyData(int count) {
+        List<MyEntity> input = Stream.generate(this::givenMyEntity).limit(count).collect(Collectors.toList());
+        myEntityRepository.saveAll(input);
+    }
+
+    private MyEntity givenMyEntity() {
+        return new MyEntity();
+    }
+
+}