标签：知识点 String firstname JPA lastname User Spring Query where
Spring JPA介绍官网：
https://docs.spring.io/spring-data/jpa/docs/2.4.3/reference/html/#repositories.core-concepts
The following table describes the keywords supported for JPA and what a method containing that keyword translates to:
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也支持xml定义：
<named-query name="User.findByLastname"> <query>select u from User u where u.lastname = ?1</query> </named-query>
通过自定义Query：
public interface UserRepository extends JpaRepository<User, Long> {
@Query("select u from User u where u.emailAddress = ?1")
User findByEmailAddress(String emailAddress);
}
Like:
public interface UserRepository extends JpaRepository<User, Long> {
@Query("select u from User u where u.firstname like %?1")
List<User> findByFirstnameEndsWith(String firstname);
}
使用Native SQL:
public interface UserRepository extends JpaRepository<User, Long> {
@Query(value = "SELECT * FROM USERS WHERE EMAIL_ADDRESS = ?1", nativeQuery = true)
User findByEmailAddress(String emailAddress);
}
一次性带分页统计：
public interface UserRepository extends JpaRepository<User, Long> {
@Query(value = "SELECT * FROM USERS WHERE LASTNAME = ?1",
countQuery = "SELECT count(*) FROM USERS WHERE LASTNAME = ?1",
nativeQuery = true)
Page<User> findByLastname(String lastname, Pageable pageable);
}
排序：
public interface UserRepository extends JpaRepository<User, Long> {
@Query("select u from User u where u.lastname like ?1%")
List<User> findByAndSort(String lastname, Sort sort);
@Query("select u.id, LENGTH(u.firstname) as fn_len from User u where u.lastname like ?1%")
List<Object[]> findByAsArrayAndSort(String lastname, Sort sort);
}
repo.findByAndSort("lannister", Sort.by("firstname"));
repo.findByAndSort("stark", Sort.by("LENGTH(firstname)"));
repo.findByAndSort("targaryen", JpaSort.unsafe("LENGTH(firstname)"));
repo.findByAsArrayAndSort("bolton", Sort.by("fn_len"));
绑定参数名形式：
public interface UserRepository extends JpaRepository<User, Long> {
@Query("select u from User u where u.firstname = :firstname or u.lastname = :lastname")
User findByLastnameOrFirstname(@Param("lastname") String lastname,
@Param("firstname") String firstname);
}
使用SpEL 表达式，可以使用动态表名，实际上是通过Domain对象对应的Entity指定表名或对象名所决定的，如果做分表应当是有用，比如同样的表结构，按年分表的查询
具体见：https://docs.spring.io/spring-data/jpa/docs/2.4.3/reference/html/#jpa.query.spel-expressions
@Entity
public class User {
@Id
@GeneratedValue
Long id;
String lastname;
}
public interface UserRepository extends JpaRepository<User,Long> {
@Query("select u from #{#entityName} u where u.lastname = ?1")
List<User> findByLastname(String lastname);
}
更新指定字段，仅更新一个表的个别字段时可以使用：
@Modifying
@Query("update User u set u.firstname = ?1 where u.lastname = ?2")
int setFixedFirstnameFor(String firstname, String lastname);
删除语句，按某些特殊字段删除时使用：
interface UserRepository extends Repository<User, Long> {
void deleteByRoleId(long roleId);
@Modifying
@Query("delete from User u where u.role.id = ?1")
void deleteInBulkByRoleId(long roleId);
}
标签：知识点,String,firstname,JPA,lastname,User,Spring,Query,where 来源： https://www.cnblogs.com/webjlwang/p/14296270.html
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