Spring-Data-JPA @Query注解 Sort排序

当我们使用方法名称很难，达到预期的查询结果，就可以使用@Query进行查询，@Query是一种添加自定义查询的便利方式

（方法名称查询见http://blog.csdn.net/niugang0920/article/details/79426521）

使用@Query注解，使用注解有两种方式，一种是JPQL的SQL语言方式，一种是原生SQL的语言.

1.User.java 实体类

1. package com.niugang.entity;
2. import javax.persistence.Column;
3. import javax.persistence.Entity;
4. import javax.persistence.GeneratedValue;
5. import javax.persistence.GenerationType;
6. import javax.persistence.Id;
7. import javax.persistence.Table;
8. //javax.persistence.Entity
9. @Entity
10. @Table(name="user")
11. public class User {
12. /**
13. *mysql 自定生成主键
14. *指示持久性提供者必须分配使用数据库标识列的实体的主键
15. */
16. @Id
17. @GeneratedValue(strategy = GenerationType.IDENTITY)  
18. @Column(name="id" ,insertable=false,updatable=false)
19. private Integer id;
20. /**
21. * @Column中的name默认和字段名相同
22. */
23. @Column(name = "name")
24. private String name;
25. @Column(name = "age")
26. private Integer age;
27. @Column(name = "phone")
28. private String phone;
29. @Column(name = "password")
30.  
31. private String password;
32.  
33.        public String getPassword() {
34. return password;
35. }
36. public void setPassword(String password) {
37. this.password = password;
38. }
39. public Integer getId() {
40. return id;
41. }
42. public void setId(Integer id) {
43. this.id = id;
44. }
45. public String getName() {
46. return name;
47. }
48. public void setName(String name) {
49. this.name = name;
50. }
51. public Integer getAge() {
52. return age;
53. }
54. public void setAge(Integer age) {
55. this.age = age;
56. }
57. public String getPhone() {
58. return phone;
59. }
60. public void setPhone(String phone) {
61. this.phone = phone;
62. }
63. @Override
64. public String toString() {
65. return "User [id=" + id + ", name=" + name + ", age=" + age + ", phone=" + phone + ", password=" + password
66. + "]";
67. }
68.  
69. }

2.UserDao.java

1. package com.niugang.dao;
2. import java.util.List;
3. import org.springframework.data.domain.Page;
4. import org.springframework.data.domain.Pageable;
5. import org.springframework.data.jpa.repository.JpaRepository;
6. import org.springframework.data.jpa.repository.Query;
7. import org.springframework.data.repository.query.Param;
8. import org.springframework.stereotype.Repository;
9. import com.niugang.entity.User;
10. /**
11.  * JpaRepository springboot已经自动配置了，也已经注入数据源了
12.  * 
13.  * @author niugang
14.  *
15.  */
16. @Repository
17. public interface UserDao extends JpaRepository<User, Integer> {
18. /**
19. * ？加数字表示占位符，？1代表在方法参数里的第一个参数，区别于其他的index，这里从1开始
20. */
21. // select * from User where name = ?1 注意不能写成*
22. @Query(value = "select u from  User u where u.name = ?1")
23. User findUserByName1(String name);
24.  
25.  
26. /**
27. * =:加上变量名，这里是与方法参数中有@Param的值匹配的，而不是与实际参数匹配的 和上面第一个原理是一样的
28. */
29. @Query(value = "select u from  User u where u.name = :name")
30.  
31. User findUserByName2(@Param("name") String username);
32.  
33.       /**
34. * 通过原生sql 进行查询
35. * 开启nativeQuery=true，在value里可以用原生SQL语句完成查询
36. */
37. @Query(nativeQuery = true, value = "select * from  user u where u.name = :name")
38. User findUserByNativeSQL(@Param("name") String username);
39.  
40.  
41. /**
42. * 模糊查询 这里的%只能放在占位的前面，后面不行
43. */
44. @Query(value = "select u from  User u where u.name like  %?1% ")
45. List<User> findUserLike(String name);
46.  
47.  
48. /**
49. * 调条件分页查询 Pageable：spring-data-jpa自带接口
50. * 
51. * @param name
52. *            :查询条件name
53. * @param page:分页对象
54. * @return
55. */
56. @Query(value = "select u from  User u where u.name like  %?1% ")
57.  
58. Page<User> findUserLikeByPage(String name, Pageable page);
59.  
60.      /**
61. * @Query查询不支持，排序并且分页
62. * 源码分析
63. * if (hasParameterOfType(method, Pageable.class)) {
64.  
65.  
66. if (!isStreamQuery()) {
67. assertReturnTypeAssignable(method, Slice.class, Page.class, List.class);
68. }
69.  
70.  
71. if (hasParameterOfType(method, Sort.class)) {
72. throw new IllegalStateException(String.format("Method must not have Pageable *and* Sort parameter. "
73. + "Use sorting capabilities on Pageble instead! Offending method: %s", method.toString()));
74. }
75. }
76. * 
77. * @param sort ：排序对象 org.springframework.data.domain.Sort
78. * @return
79. */
80. @Query(value = "select u from  User u")
81. List<User> findUserLikeBySort(Sort sort);
82.  
83. }

3.   findUserLikeByPage(String name, Pageable page)接口解释：

1.  public Page<User> findUserByPage(String name) {
2.   PageRequest pageRequest = new PageRequest(0, 4);
3.   return userDao.findUserLikeByPage(name, pageRequest);
4.  
5. }

4.排序测试代码

1. /**
2. * 单条件排序
3. */
4. public List<User> findListSortSingleCondition(){
5. //id升序查询
6. Sort sort = new Sort(Sort.Direction.ASC,"id");
7. return userDao.findUserLikeBySort(sort);
8. }
9. /**
10. * 多条件排序
11. */
12. public List<User> findListSortMultiCondition(){
13. List<Order> orders=new ArrayList<Order>();
14. Order orderId = new Sort.Order(Sort.Direction.DESC,"id");
15. Order orderAge = new Sort.Order(Sort.Direction.DESC,"age");
16. orders.add(orderId);
17. orders.add(orderAge);
18. Sort sort = new Sort(orders);
19. return userDao.findUserLikeBySort(sort);
20. }