登录
当前位置： 首页 > 知识库问答 >
问题：

Spring保存带有外键的复合主键

单于承
2023-03-14

我在使用复合主键创建实体时遇到问题，该键也是外键。这是我的表和关系表原理图。当我想创建新闻实体时，我收到了带有null creatingnews的错误消息。新闻翻译有复合主键，外键引用到新闻表。

这是我的代码：

新闻聚合

@AggregateRoot
@Entity
@Table(name = "news")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class NewsAggregate extends AuditingAggregateRoot implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "news_id")
    private Long newsId;

    @ManyToOne
    @JoinColumn(name = "id")
    private UserAggregate authorId;

    @Column(name = "publish_time")
    private ZonedDateTime publishTime;

    @Column(name = "published", nullable = false)
    private boolean published = false;

    @ManyToMany
    @JoinTable(
        name = "tags_news",
        joinColumns = {@JoinColumn(name = "news_id", referencedColumnName = "news_id")},
        inverseJoinColumns = {@JoinColumn(name = "tag", referencedColumnName = "tag")})
    @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
    private Set<Tags> tags = new HashSet<Tags>();

    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL,
        orphanRemoval = true)
    private List<NewsTranslation> newsTranslation;



    public NewsAggregate(UserAggregate authorId, Set<Tags> tags, String langCode,
                         String title, String shortDescription, String longDescription) {
        this.authorId = authorId;
        this.tags = tags;
        newsTranslation.add(
            new NewsTranslation(this, langCode, title, shortDescription, longDescription)
        );


    }

//Getters, equal, hashCode

新闻翻译

@Entity
@Table(name = "news_translation")
/*@IdClass(NewsLangId.class)*/
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class NewsTranslation implements Serializable {

    private static final long serialVersionUID = 7576921328990303444L;

    @EmbeddedId
    private NewsLangId newsLangId;

    @Column(name = "title", length = TITLE_MAX_LENGTH, nullable = false)
    private String title;

    @Column(name = "short_description", length = SHORT_DESC_MAX_LENGTH, nullable = false)
    private String shortDescription;

    @Column(name = "long_description", nullable = false)
    private String longDescription;

    @ManyToOne
    @JoinColumn(name = "news_id", insertable = false, updatable = false)
    private NewsAggregate newsAggregate;

    @ManyToOne
    @JoinColumn(name = "lang_code", insertable = false, updatable = false)
    private Languages languages;

    public NewsTranslation() {
    }

    protected NewsTranslation(NewsAggregate newsAggregate, String langCode,String title, String shortDescription, String longDescription) {
        System.out.println(">>>>>>>>>>>>>>>.. NewsTranslation constructor");
        this.title = title;
        this.shortDescription = shortDescription;
        this.longDescription = longDescription;
        this.newsAggregate = newsAggregate;
        this.languages = new Languages();
        this.newsLangId = new NewsLangId(this.newsAggregate.getId(), langCode);
        System.out.println(">>>>>>>>> NewsTranslation : title = "+this.title+", shortDescription = "+this.shortDescription+
        ", longDescription = "+this.longDescription+", newsAggregate = "+this.newsAggregate +", languages = "+this.languages);

    }

// getters, setters

标签

@Entity
@Table(name = "tags")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class Tags implements Serializable {
private static final long serialVersionUID = 2995101252921266446L;

@Id
@Column(name = "tag", length = TAG_MAX_LENGTH, unique = true)
private String tag;

public Tags() {
}

private Tags(Builder builder) {
    this.tag = Preconditions.checkNotNull(builder.tag);
}

public void setTag(String tag) {
    this.tag = tag;
}

新闻语言ID

@Embeddable
public class NewsLangId implements Serializable {

private static final long serialVersionUID = -4822628791720244835L;

@Column(name = "news_id")
private long newsId;
@Column(name = "lang_code")
private String langCode;

public NewsLangId() {
}

public NewsLangId(long newsId, String langCode) {
    System.out.println("Create NewsLangId: "+newsId+", "+langCode);
    this.newsId = newsId;
    this.langCode = langCode;
}

// getters, setters, equal, hashcode

在NewsFactory中，我希望使用NewsTranslation创建NewsAggregate，但有错误消息NullPointer。

新闻工厂

Set<Tags> tagsSet = new HashSet<Tags>(tagsRepository.findAll());
        UserAggregate login = userRepository.findOneByLogin("admin").get();


        NewsAggregate news = new NewsAggregate(login,tagsSet, createNewsDto.getLangCode(), createNewsDto.getTitle(),
            createNewsDto.getShortDescription(),createNewsDto.getLongDescription());

        log.info(">>>>>>>>>>>> NewsFactory: newsAggregate = "+news);

        return news;

错误：

java.lang.NullPointerException: null
    at it.seiton.aexea.domain.model.news.NewsTranslation.<init>(NewsTranslation.java:55)
    at it.seiton.aexea.domain.model.news.NewsAggregate.<init>(NewsAggregate.java:61)
    at it.seiton.aexea.domain.model.news.NewsFactory.createNews(NewsFactory.java:55)
    at it.seiton.aexea.domain.service.impl.NewsServiceDefault.createNews(NewsServiceDefault.java:29)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
    at com.sun.proxy.$Proxy184.createNews(Unknown Source)
    at it.seiton.aexea.web.rest.NewsResource.createNews(NewsResource.java:43)
    at it.seiton.aexea.web.rest.NewsResource$$FastClassBySpringC530334.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:720)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:85)
    at it.seiton.aexea.aop.logging.LoggingAspect.logAround(LoggingAspect.java:51)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:620)
    at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:609)
    at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:68)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:59)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:655)
    at it.seiton.aexea.web.rest.NewsResource$$EnhancerBySpringCGLIB$$c9591bb7.createNews(<generated>)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:817)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:731)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:968)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:870)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:844)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
    at com.codahale.metrics.servlet.AbstractInstrumentedFilter.doFilter(AbstractInstrumentedFilter.java:104)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at com.hazelcast.web.WebFilter.doFilter(WebFilter.java:360)
    at io.undertow..core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration$ApplicationContextHeaderFilter.doFilterInternal(EndpointWebMvcAutoConfiguration.java:237)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:92)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:112)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:207)
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176)
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346)
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
    at org.springframework.web.filter.OncePerRequestFilter.doOncePerRequestFilter.java:107)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:87)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:121)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
    at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
    at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
    at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
    at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.security.handlers.AbstractConfiityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
    at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
    at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
    at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
    at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet.handlers.SessionRestoringHandler.handleRequest(SessionRestoringHandler.java:119)
    at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:284)
    at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263)
    at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
    at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
    at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
    at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

对我的英语很抱歉。

共有1个答案

王曜文
2023-03-14

我通过更改生成的主键解决了我的问题。现在java生成id，而不是postgresql。

新闻聚合

@AggregateRoot
@Entity
@Table(name = "news")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class NewsAggregate extends AuditingAggregateRoot implements Serializable {
    private static final Logger log = LoggerFactory.getLogger(NewsAggregate.class);


@Id
@Column(name = "news_id")
private String newsId;

@ManyToOne
@JoinColumn(name = "author_id", referencedColumnName = "id")
private UserAggregate authorId;

@Column(name = "publish_date")
private ZonedDateTime publishTime = null;

@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(
    name = "tags_news",
    joinColumns = {@JoinColumn(name = "news_id", referencedColumnName = "news_id")},
    inverseJoinColumns = {@JoinColumn(name = "tag", referencedColumnName = "tag")})
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
private Set<Tags> tags = new HashSet<Tags>();

@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "news_id", referencedColumnName = "news_id")
@Fetch(FetchMode.JOIN)
private List<NewsTranslation> newsTranslation = new ArrayList<NewsTranslation>();

public NewsAggregate(Set<Tags> tags, UserAggregate authorId) {
    this.newsId = generateId(authorId.getId());
    this.tags = tags;
    this.authorId = authorId;
    this.publishTime = ZonedDateTime.now();
}

private NewsAggregate(Builder builder) {
    this.authorId = Preconditions.checkNotNull(builder.authorId);
    this.publishTime = builder.publishTime;
    this.tags = Preconditions.checkNotNull(builder.tags);
    this.newsTranslation = Preconditions.checkNotNull(builder.newsTranslation);
}

private String generateId(long userId) {
    return ZonedDateTime.now().toInstant().toEpochMilli() + "_" + userId;
}

public static NewsAggregate createNews(Set<Tags> tags, UserAggregate authorId, CreateNewsDto createNewsDto) {

    NewsAggregate news = new NewsAggregate(tags, authorId);
    log.info(">>>>>>>>>>>>>>>>>> news_id = "+news.getNewsId());
    NewsLangId newsLangId = new NewsLangId(news.getNewsId(), "en");

    NewsTranslation newsTranslation = new NewsTranslation(newsLangId, createNewsDto.getTitle(),
        createNewsDto.getShortDescription(), createNewsDto.getLongDescription());

    List<NewsTranslation> newsTranslations = new ArrayList<>();
    newsTranslations.add(newsTranslation);

    news.addTranslation(newsTranslations);
    return news;
}

private void addTranslation(List<NewsTranslation> newsTranslations) {
    this.newsTranslation = newsTranslations;
}

谢谢大家的关注。我希望这将是有益的。

 类似资料：
  • 带有复合主键的Spring数据表

    问题内容： 我使用spring数据休息作为基础。但是当实体具有复合主键时，我不知道如何通过提供主键来获得实体。 河类： RiverPK课程： RiverDAO类： 然后，我可以通过调用get http：// localhost：8080 / river / 获取河流数据，还可以通过调用post http：// localhost：8080 / river / {river json} 为db创建新

  • 带有部分组合主键的休眠外键

    问题内容： 我必须与Hibernate合作，但我不确定如何解决此问题，我有2个具有1..n关系的表，如下所示： 如何使用Hibernate进行管理？ 我不知道如何声明将包含主键一部分的外键。 我的数据库架构是从Hibernate模型生成的。 问题答案： 我找到了解决此问题的两种方法。 第一个是一种解决方法，没有第二个那么整洁。 将实体的主键定义为包含，和的复合键，首先将假定为主键的内容定义为唯一约

  • 具有复合主键和外键的JPA实体

    我有一个实体，它的复合主键由两个字段组成，其中一个也是复合外键的一部分。 背景:我有实体<代码>人员 、<代码>区域 和<代码>会话 。 与具有多对多关系，使用称为“和实体。 所以，我有，主键为（，）。本身是的外键。 也有一个字段。我希望（，）是的复合外键。 我的PersonSession代码： } 这看起来不错，它在数据库中创建了所有正确的关系。当我尝试插入个性化会话对象时，问题就出现了——ar

  • 将复合外键映射到复合主键

    我在jpa/Hibernate中映射复合键时遇到了问题。父实体和子实体都具有复合主键。 在运行时保存它时会出现以下异常： 我认为这是虚假的，因为有getter和setter。如果在priceRequestLegModel上使用mappedby=“leg”，在allocationModel上使用@mapsid，也会出现同样的错误。有人能指出我在这里做错了什么吗？

  • Hibernate-复合主键包含外键

    问题内容： 我有一个类似的问题，如下所示，但解决方案无法解决我的问题。 休眠复合主键包含复合外键，如何映射 我正在尝试加入2个表，每个表都有一个带有部分外键引用的复合主键。 在一个： 在BPK中： 上面的方法给我这个异常： 你能帮忙吗？ 问题答案： 假设f1和F2唯一标识A并存在于APK中，则可以通过几种方式使用JPA 2.0的派生ID。最容易显示的是： 这里的关键点是B对A的引用控制了外键字段f

  • Hibernate-复合主键包含外键

    问题内容： 我有一个类似的问题，如下所示，但解决方案无法解决我的问题。 休眠复合主键包含复合外键，如何映射 我正在尝试加入2个表，每个表都有一个带有部分外键引用的复合主键。 在一个： 在BPK中： 上面的方法给我这个异常： 你能帮忙吗？ 问题答案： 假设f1和F2唯一标识A并存在于APK中，则可以通过几种方式使用JPA 2.0的派生ID。最容易显示的是： 这里的关键点是B对A的引用控制了外键字段f

相关问答

具有复合主键的spring数据Rest使用复合主键作为外键Spring data r2dbc-复合主键JPA如何制作复合主键的复合外键部分CrudRepository，不能使用IdClass保存具有复合主键的实体

相关文章

使用复合主键作为外键Hibernate复合主键包含复合外键，如何映射复合主键将主键更改为复合键（主键已存在）JPA如何使复合外键成为复合主键的一部分

相关阅读

MySQL外键约束一文带你了解堆内存和堆外内存MySQL主键自增长Python关键字（保留字）弱键集合WeakHashMap的原理以及ConcurrentCache的原理

相关工具

外存图片下载和保存自定义的拨号键盘右键助手带AI的2048游戏

相关文档

IPsec VPN 服务器一键安装脚本SQL 合计函数Pandas Cookbook 带注释源码皮卡智能 一键抠图神器 API 文档外业精灵产品文档
快捷导航： 新手教程 算法原理 架构设计 Java进阶 数据库进阶 大厂专栏 面试经验 编程笔记 编程问答 所有专题 文档资料 工具软件 电子书籍 小牛导航
在线工具： 房贷计算器 个税计算器 Linux命令查询 Json格式化 正则表达式 颜色转换 AES加解密 SHA1加密 MD5加密 毒鸡汤 字数统计 随机密码生成 进制转换 Base64编解码 励志句子
Copyright © 2019-2024 小牛知识库@xnip.cn. All Rights Reserved.