spring data jpa annotation examples (#4309)

persistence-modules/spring-jpa/src/main/java/org/baeldung/annotations/MyUtilityRepository.java

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+package org.baeldung.annotations;
+
+import java.io.Serializable;
+import java.util.Optional;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.NoRepositoryBean;
+
+@NoRepositoryBean
+public interface MyUtilityRepository<T, ID extends Serializable> extends CrudRepository<T, ID> {
+
+    Optional<T> findById(ID id);
+
+}

persistence-modules/spring-jpa/src/main/java/org/baeldung/annotations/Person.java

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+package org.baeldung.annotations;
+
+import java.util.Date;
+
+import javax.persistence.Entity;
+import javax.persistence.NamedStoredProcedureQueries;
+import javax.persistence.NamedStoredProcedureQuery;
+import javax.persistence.ParameterMode;
+import javax.persistence.StoredProcedureParameter;
+
+import org.baeldung.persistence.multiple.model.user.User;
+import org.springframework.data.annotation.CreatedBy;
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.annotation.LastModifiedBy;
+import org.springframework.data.annotation.Transient;
+
+@Entity
+@NamedStoredProcedureQueries({ 
+    @NamedStoredProcedureQuery(
+        name = "count_by_name", 
+        procedureName = "person.count_by_name", 
+        parameters = { 
+                @StoredProcedureParameter(
+                    mode = ParameterMode.IN, 
+                    name = "name", 
+                    type = String.class),
+                @StoredProcedureParameter(
+                    mode = ParameterMode.OUT, 
+                    name = "count", 
+                    type = Long.class) 
+                }) 
+})
+public class Person {
+
+    @Id
+    private Long id;
+
+    @Transient
+    private int age;
+
+    @CreatedBy
+    private User creator;
+
+    @LastModifiedBy
+    private User modifier;
+
+    @CreatedDate
+    private Date createdAt;
+
+    @LastModifiedBy
+    private Date modifiedAt;
+
+}

persistence-modules/spring-jpa/src/main/java/org/baeldung/annotations/PersonRepository.java

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+package org.baeldung.annotations;
+
+import javax.persistence.LockModeType;
+
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.jpa.repository.query.Procedure;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface PersonRepository extends MyUtilityRepository<Person, Long> {
+
+    @Lock(LockModeType.NONE)
+    @Query("SELECT COUNT(*) FROM Person p")
+    long getPersonCount();
+
+    @Query("FROM Person p WHERE p.name = :name")
+    Person findByName(@Param("name") String name);
+
+    @Query(value = "SELECT AVG(p.age) FROM person p", nativeQuery = true)
+    Person getAverageAge();
+
+    @Procedure(name = "count_by_name")
+    long getCountByName(@Param("name") String name);
+
+    @Modifying
+    @Query("UPDATE Person p SET p.name = :name WHERE p.id = :id")
+    void changeName(@Param("id") long id, @Param("name") String name);
+
+}