{"id":10008378,"date":"2024-02-21T10:56:55","date_gmt":"2024-02-21T02:56:55","guid":{"rendered":"https:\/\/blog.itmax.cn\/?p=10008378"},"modified":"2024-02-21T10:56:55","modified_gmt":"2024-02-21T02:56:55","slug":"spring-boot-jpa%ef%bc%9a%e7%ae%80%e4%bb%8b%e3%80%81%e6%b3%a8%e8%a7%a3%e4%b8%8e%e6%9f%a5%e8%af%a2%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10008378","title":{"rendered":"Spring Boot JPA\uff1a\u7b80\u4ecb\u3001\u6ce8\u89e3\u4e0e\u67e5\u8be2\u65b9\u6cd5"},"content":{"rendered":"

JPA \u662f\u4ec0\u4e48<\/h2>\n

Java Persistence API\uff08JPA\uff09\u662fJava EE\u7684\u4e00\u90e8\u5206\uff0c\u7528\u4e8e\u7b80\u5316Java\u5e94\u7528\u7a0b\u5e8f\u4e2d\u7684\u6570\u636e\u6301\u4e45\u5316\u64cd\u4f5c\u3002Spring Boot\u6846\u67b6\u96c6\u6210\u4e86JPA\uff0c\u63d0\u4f9b\u4e86\u4e00\u79cd\u65b9\u4fbf\u7684\u65b9\u5f0f\u6765\u8fdb\u884c\u5bf9\u8c61\u5173\u7cfb\u6620\u5c04\uff08ORM\uff09\uff0c\u5c06Java\u5bf9\u8c61\u6620\u5c04\u5230\u6570\u636e\u5e93\u8868\u4e2d\u3002\u8fd9\u4f7f\u5f97\u5f00\u53d1\u8005\u80fd\u591f\u901a\u8fc7\u4f7f\u7528Java\u7c7b\u548c\u6ce8\u89e3\uff0c\u800c\u4e0d\u662f\u7e41\u7410\u7684SQL\u8bed\u53e5\uff0c\u6765\u8fdb\u884c\u6570\u636e\u5e93\u64cd\u4f5c\u3002<\/p>\n

JPA \u7684\u6ce8\u89e3<\/h2>\n

\u5b9e\u4f53\u7c7b\u76f8\u5173\u6ce8\u89e3<\/h3>\n

@Entity<\/h4>\n

\u5c06Java\u7c7b\u6807\u8bb0\u4e3aJPA\u5b9e\u4f53\uff0c\u7528\u4e8e\u6620\u5c04\u5230\u6570\u636e\u5e93\u8868\u3002<\/p>\n

@Entity\npublic class User {\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@Table<\/h4>\n
\u7528\u4e8e\u6307\u5b9a\u5b9e\u4f53\u7c7b\u4e0e\u6570\u636e\u5e93\u8868\u7684\u6620\u5c04\u5173\u7cfb\uff0c\u53ef\u4ee5\u6307\u5b9a\u8868\u7684\u540d\u79f0\u7b49\u4fe1\u606f\u3002<\/p>\n
@Entity\n@Table(name = "users")\npublic class User {\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
\u5982\u679c\u6ca1\u6709 @Table \u6ce8\u89e3\u4ee5\u8bbe\u7f6e\u8868\u540d\u7684\u8bdd\uff0c\u5219\u4ee5\u7c7b\u540d\u4e3a\u8868\u540d\uff0c\u4e14\u5927\u5c0f\u5199\u654f\u611f\u3002<\/p>\n
\u4e3b\u952e\u76f8\u5173\u6ce8\u89e3<\/h3>\n
@Id<\/h4>\n
\u5b9a\u4e49\u5b9e\u4f53\u7c7b\u7684\u4e3b\u952e\u5b57\u6bb5\u3002<\/p>\n
@Entity\npublic class User {\n    @Id\n    private Long id;\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@GeneratedValue<\/h4>\n
\u5b9a\u4e49\u4e3b\u952e\u7684\u751f\u6210\u7b56\u7565\u3002<\/p>\n
@Entity\npublic class User {\n    @Id\n    \/\/ \u8bbe\u7f6e\u4e3b\u952e\u7684\u81ea\u589e\u7b56\u7565\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
\u5b57\u6bb5\u4e0e\u5217\u7684\u6620\u5c04\u6ce8\u89e3<\/h3>\n
@Column<\/h4>\n
\u7528\u4e8e\u5b9a\u4e49\u5b9e\u4f53\u7c7b\u5b57\u6bb5\u4e0e\u6570\u636e\u5e93\u8868\u5217\u7684\u6620\u5c04\u5173\u7cfb\u3002\u53ef\u4ee5\u6307\u5b9a\u5217\u7684\u540d\u79f0\u3001\u957f\u5ea6\u3001\u662f\u5426\u5141\u8bb8\u4e3anull\u7b49\u5c5e\u6027\u3002<\/p>\n
@Entity\npublic class User {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @Column(name = "username", length = 50, nullable = false)\n    private String username;\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@Transient<\/h4>\n
\u8868\u793a\u8be5\u5b57\u6bb5\u4e0d\u9700\u8981\u6301\u4e45\u5316\u5230\u6570\u636e\u5e93\u3002<\/p>\n
@Entity\npublic class User {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @Transient\n    private transientField; \/\/ Will not be persisted to the database\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
\u5173\u7cfb\u6620\u5c04\u6ce8\u89e3<\/h3>\n
@OneToOne<\/h4>\n
@OneToMany<\/h4>\n
@ManyToOne<\/h4>\n
@ManyToMany<\/h4>\n
@JoinColumn<\/h4>\n
\u67e5\u8be2\u76f8\u5173\u6ce8\u89e3<\/h3>\n
@Query<\/h4>\n
\u7528\u4e8e\u5b9a\u4e49JPQL\u6216\u539f\u751fSQL\u67e5\u8be2\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    private Long id;\n\n    private String name;\n    private double price;\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}\n\n@Repository\npublic interface ProductRepository extends JpaRepository<Product, Long> {\n\n    \/\/ \u4f7f\u7528JPQL\u67e5\u8be2\u6240\u6709\u4ea7\u54c1\n    @Query("SELECT p FROM Product p")\n    List<Product> findAllProducts();\n\n    \/\/ \u4f7f\u7528JPQL\u67e5\u8be2\u4ef7\u683c\u4f4e\u4e8e\u6307\u5b9a\u503c\u7684\u4ea7\u54c1\n    @Query("SELECT p FROM Product p WHERE p.price < :maxPrice")\n    List<Product> findProductsByPrice(@Param("maxPrice") double maxPrice);\n}<\/code><\/pre>\n
@NamedQuery<\/h4>\n
\u7528\u4e8e\u5b9a\u4e49\u547d\u540d\u67e5\u8be2\u3002<\/p>\n
@Entity\n@NamedQuery(name = "Product.findByProductName", query = "SELECT p FROM Product p WHERE p.productName = :productName")\npublic class Product {\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}\n\n@Repository\npublic interface ProductRepository extends JpaRepository<Product, Long> {\n    @Query(name = "Product.findByProductName")\n    Product findByProductName(@Param("productName") String productName);\n}<\/code><\/pre>\n
@NamedQueries<\/h4>\n
\u7528\u4e8e\u5b9a\u4e49\u4e00\u7ec4\u547d\u540d\u67e5\u8be2\u3002<\/p>\n
@Entity\n@NamedQueries({\n    @NamedQuery(name = "Product.findAll", query = "SELECT p FROM Product p"),\n    @NamedQuery(name = "Product.findByPrice", query = "SELECT p FROM Product p WHERE p.price < :maxPrice")\n})\npublic class Product {\n    @Id\n    private Long id;\n\n    private String name;\n    private double price;\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}\n\n@Repository\npublic interface ProductRepository extends JpaRepository<Product, Long> {\n\n    @Query(name = "Product.findAll")\n    List<Product> findAllProducts();\n\n    @Query(name = "Product.findByPrice")\n    List<Product> findProductsByPrice(@Param("maxPrice") double maxPrice);\n}<\/code><\/pre>\n
\u7248\u672c\u63a7\u5236\u6ce8\u89e3<\/h3>\n
@Version<\/h4>\n
\u786e\u4fdd\u5728\u5e76\u53d1\u73af\u5883\u4e0b\u5bf9\u5b9e\u4f53\u7684\u4fee\u6539\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u3002\u5b83\u901a\u5e38\u4e0e\u6574\u6570\u7c7b\u578b\u7684\u5b57\u6bb5\u4e00\u8d77\u4f7f\u7528\uff0c\u8be5\u5b57\u6bb5\u5728\u6bcf\u6b21\u66f4\u65b0\u65f6\u9012\u589e\uff0c\u4ece\u800c\u5141\u8bb8\u68c0\u6d4b\u5e76\u53d1\u66f4\u65b0\u51b2\u7a81\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    private Long id;\n\n    private String name;\n    private double price;\n\n    @Version\n    private int version; \/\/ \u4e50\u89c2\u9501\u7248\u672c\u63a7\u5236\u5b57\u6bb5\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
\u751f\u547d\u5468\u671f\u56de\u8c03\u6ce8\u89e3<\/h3>\n
@PrePersist<\/h4>\n
\u5728\u5b9e\u4f53\u88ab\u6301\u4e45\u5316\u524d\u8c03\u7528\u7684\u65b9\u6cd5\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @PrePersist\n    public void prePersist() {\n        \/\/ \u4e00\u4e9b\u903b\u8f91\n    }\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@PostPersist<\/h4>\n
\u5728\u5b9e\u4f53\u88ab\u6301\u4e45\u5316\u540e\u8c03\u7528\u7684\u65b9\u6cd5\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @PostPersist\n    public void postPersist() {\n        \/\/ \u4e00\u4e9b\u903b\u8f91\n    }\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@PreUpdate<\/h4>\n
\u5728\u5b9e\u4f53\u88ab\u66f4\u65b0\u524d\u8c03\u7528\u7684\u65b9\u6cd5\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @PreUpdate\n    public void preUpdate() {\n        \/\/ \u4e00\u4e9b\u903b\u8f91\n    }\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@PostUpdate<\/h4>\n
\u5728\u5b9e\u4f53\u88ab\u66f4\u65b0\u540e\u8c03\u7528\u7684\u65b9\u6cd5\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @PostUpdate\n    public void postUpdate() {\n        \/\/ \u4e00\u4e9b\u903b\u8f91\n    }\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@PreRemove<\/h4>\n
\u5728\u5b9e\u4f53\u88ab\u5220\u9664\u524d\u8c03\u7528\u7684\u65b9\u6cd5\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @PreRemove\n    public void preRemove() {\n        \/\/ \u4e00\u4e9b\u903b\u8f91\n    }\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
@PostRemove<\/h4>\n
\u5728\u5b9e\u4f53\u88ab\u5220\u9664\u540e\u8c03\u7528\u7684\u65b9\u6cd5\u3002<\/p>\n
@Entity\npublic class Product {\n    @Id\n    @GeneratedValue(strategy = GenerationType.IDENTITY)\n    private Long id;\n\n    @PostRemove\n    public void postRemove() {\n        \/\/ \u4e00\u4e9b\u903b\u8f91\n    }\n\n    \/\/ \u5176\u4ed6\u5b57\u6bb5\u6216\u65b9\u6cd5\n}<\/code><\/pre>\n
\u9664\u4e86\u4e0a\u8ff0\u63d0\u5230\u7684\u6ce8\u89e3\uff0cJPA\u8fd8\u6709\u5176\u4ed6\u6ce8\u89e3\uff1a<\/p>\n
\u7ee7\u627f\u6620\u5c04\u6ce8\u89e3 @MappedSuperclass\u3001\u679a\u4e3e\u6620\u5c04\u6ce8\u89e3 @Enumerated\u3001Lob\u6ce8\u89e3 @Lob\u3001\u8868\u7684\u7d22\u5f15\u76f8\u5173\u6ce8\u89e3 @Index \u7b49\u7b49\u3002<\/p>\n
\u8fd9\u91cc\u4e0d\u8fc7\u591a\u6df1\u5165\u3002<\/p>\n
JPA \u7684\u67e5\u8be2\u65b9\u6cd5<\/h2>\n
\u57fa\u4e8e\u65b9\u6cd5\u540d\u79f0\u7684\u67e5\u8be2<\/h3>\n
\u6211\u4eec\u6700\u5e38\u7528\u7684\u67e5\u8be2\u65b9\u6cd5\u3002\u80fd\u591f\u8986\u76d6\u7edd\u5927\u90e8\u5206\u67e5\u8be2\u9700\u6c42\u3002<\/p>\n
public interface UserRepository extends JpaRepository<User, Long> {\n    User findByUsername(String username);\n\n    User findByUsernameAndEmail(String username, String email);\n\n    List<User> findByEmailLike(String email);\n}<\/code><\/pre>\n
JPQL\u67e5\u8be2\uff08@Query\u3001@NamedQuery\u3001@NamedQueries\u6ce8\u89e3\uff09<\/h3>\n
\u7528\u6cd5\u4e0e\u4e0a\u6587\u4e2d\u7684\u6ce8\u89e3\u4e2d\u7684\u793a\u4f8b\u76f8\u540c\u3002<\/p>\n
JPQL\u4e0eSQL\u8bed\u53e5\u5b58\u5728\u4e00\u4e9b\u7ec6\u5fae\u7684\u5dee\u522b\uff0c\u53ef\u4ee5\u7406\u89e3\u4e3a\u65b9\u8a00\u3002\u5177\u4f53\u60c5\u51b5\u7528\u5230\u65f6\u518d\u67e5\u770b\u6587\u6863\u5373\u53ef\u3002<\/p>\n
Native SQL\u67e5\u8be2\uff08@Query\uff09<\/h3>\n
@Query(value = "SELECT * FROM users WHERE username = ?1", nativeQuery = true)\nUser findByNativeQuery(String username);<\/code><\/pre>\n
\u52a8\u6001\u67e5\u8be2<\/h3>\n
\u4f7f\u7528Criteria API\u8fdb\u884c\u52a8\u6001\u67e5\u8be2\u3002<\/p>\n
\u5b83\u63d0\u4f9b\u4e86\u4e00\u79cd\u57fa\u4e8e\u7c7b\u578b\u5b89\u5168\u7684\u67e5\u8be2\u673a\u5236\uff0c\u5141\u8bb8\u5f00\u53d1\u8005\u4ee5\u9762\u5411\u5bf9\u8c61\u7684\u65b9\u5f0f\u6784\u5efa\u67e5\u8be2\u6761\u4ef6\uff0c\u800c\u4e0d\u5fc5\u7f16\u5199\u5b57\u7b26\u4e32\u5f62\u5f0f\u7684 JPQL\uff08Java Persistence Query Language\uff09\u67e5\u8be2\u8bed\u53e5\u3002<\/p>\n
Criteria API \u57fa\u672c\u7528\u6cd5\uff1a<\/p>\n
\/\/ \u81ea\u5b9a\u4e49\u7684\u52a8\u6001\u67e5\u8be2\u65b9\u6cd5\n@Override\npublic List<Product> findProductsByCriteria(String name) {\n  CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();\n  CriteriaQuery<Product> query = criteriaBuilder.createQuery(Product.class);\n  Root<Product> root = query.from(Product.class);\n\n  \/\/ \u6dfb\u52a0\u67e5\u8be2\u6761\u4ef6\n  Predicate condition = criteriaBuilder.equal(root.get("name"), name);\n  query.where(condition);\n\n  \/\/ \u6267\u884c\u67e5\u8be2\n  List<Product> products = entityManager.createQuery(query).getResultList();\n}<\/code><\/pre>\n
\u52a8\u6001\u67e5\u8be2\uff1a<\/p>\n
\npublic class ProductRepositoryCustomImpl implements ProductRepositoryCustom {\n\n    \/\/ \u81ea\u5b9a\u4e49\u7684\u52a8\u6001\u67e5\u8be2\u65b9\u6cd5\n    @Override\n    public List<Product> findProductsByCriteria(String name, Double maxPrice) {\n        CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();\n        CriteriaQuery<Product> query = criteriaBuilder.createQuery(Product.class);\n        Root<Product> root = query.from(Product.class);\n\n        List<Predicate> conditions = new ArrayList<>();\n\n        \/\/ \u52a8\u6001\u6dfb\u52a0\u67e5\u8be2\u6761\u4ef6\n        if (name != null && !name.isEmpty()) {\n            conditions.add(criteriaBuilder.equal(root.get("name"), name));\n        }\n        if (maxPrice != null) {\n            conditions.add(criteriaBuilder.lessThanOrEqualTo(root.get("price"), maxPrice));\n        }\n\n        \/\/ \u6784\u5efa\u67e5\u8be2\u6761\u4ef6\n        query.where(conditions);\n\n        \/\/ \u6267\u884c\u67e5\u8be2\n        return entityManager.createQuery(query).getResultList();\n    }\n}<\/code><\/pre>\n
\u5e0c\u671b\u8fd9\u7bc7\u6587\u7ae0\u5bf9\u4f60\u6709\u5e2e\u52a9\uff01<\/p>\n
\u53c2\u8003\u8d44\u6599<\/h2>\n
https:\/\/docs.spring.io\/spring-data\/jpa\/reference\/jpa.html<\/a><\/p>\n
https:\/\/segmentfault.com\/a\/1190000044593935<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
JPA \u662f\u4ec0\u4e48 Java Persistence API\uff08JPA\uff09\u662fJava EE\u7684\u4e00\u90e8\u5206\uff0c\u7528\u4e8e\u7b80\u5316Java\u5e94 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10008378","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10008378","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10008378"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10008378\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10008378"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10008378"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10008378"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}