Question

我正在尝试使用MySQL数据库启动spring boot项目，但是数据库存在一些问题。我尝试启动我的应用程序，并且服务器正在运行，但是休眠时不创建Tables等。

这是我的代码：

用户实体

 @Entity
   public class User {
      @Id
      @GeneratedValue(strategy = IDENTITY)
      private Long id;

      private String firstName;
      private String lastName;

      private String email;

      private String password;
      private String description;
      private String profile_photo;

      private LocalDate create;
      private LocalDate update;

      @OneToMany(mappedBy = "eventOwner")
      private List<Event> ownedEvents;

           public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getFirstName() {
    return firstName;
}

public void setFirstName(String firstName) {
    this.firstName = firstName;
}

public String getLastName() {
    return lastName;
}

public void setLastName(String lastName) {
    this.lastName = lastName;
}

public String getEmail() {
    return email;
}

public void setEmail(String email) {
    this.email = email;
}

public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public String getProfile_photo() {
    return profile_photo;
}

public void setProfile_photo(String profile_photo) {
    this.profile_photo = profile_photo;
}

public LocalDate getCreate() {
    return create;
}

public void setCreate(LocalDate create) {
    this.create = create;
}

public LocalDate getUpdate() {
    return update;
}

public void setUpdate(LocalDate update) {
    this.update = update;
}

public List<Event> getOwnedEvents() {
    return ownedEvents;
}

public void setOwnedEvents(List<Event> ownedEvents) {
    this.ownedEvents = ownedEvents;
}}

事件实体

   @Entity
   @Table(name = "events")
   public class Event {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

private Double longitude;
private Double latitude;

private String description;
private String header;

private LocalDate startData;
private LocalDate endData;
private LocalDate creat;
private LocalDate update;
private Filters filters;

@ManyToOne
@JoinColumn(name = "owner_id")
private User eventOwner;

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public Double getLongitude() {
    return longitude;
}

public void setLongitude(Double longitude) {
    this.longitude = longitude;
}

public Double getLatitude() {
    return latitude;
}

public void setLatitude(Double latitude) {
    this.latitude = latitude;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public String getHeader() {
    return header;
}

public void setHeader(String header) {
    this.header = header;
}

public LocalDate getStartData() {
    return startData;
}

public void setStartData(LocalDate startData) {
    this.startData = startData;
}

public LocalDate getEndData() {
    return endData;
}

public void setEndData(LocalDate endData) {
    this.endData = endData;
}

public LocalDate getCreat() {
    return creat;
}

public void setCreat(LocalDate creat) {
    this.creat = creat;
}

public LocalDate getUpdate() {
    return update;
}

public void setUpdate(LocalDate update) {
    this.update = update;
}

public Filters getFilters() {
    return filters;
}

public void setFilters(Filters filters) {
    this.filters = filters;
}

public User getEventOwner() {
    return eventOwner;
}

public void setEventOwner(User eventOwner) {
    this.eventOwner = eventOwner;
}

}

这是我的属性：

spring.datasource.url= jdbc:mysql://localhost:3306/some_database? 
requireSSL=false&useSSL=false
spring.datasource.username= user
spring.datasource.password= passw 
logging.level.org.hibernate.SQL= DEBUG
spring.jpa.hibernate.ddl-auto = create-drop
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL55Dialect

这是我得到的错误

org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing 
DDL "alter table events drop foreign key FKg0mkvgsqn8584qoql6a2rxheq" via 
JDBC Statement

和

org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing 
DDL "create table events (id bigint not null auto_increment, creat date, 
description varchar(255), end_data date, event_type integer, max_age 
integer not null, min_age integer not null, open_to_changes bit not null, 
pets_allowed bit not null, price_range integer, smoking_allowed bit not 
null, header varchar(255), latitude double precision, longitude double 
precision, start_data date, update date, owner_id bigint, primary key (id)) 
engine=InnoDB" via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) ~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:440) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:424) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:315) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:166) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:135) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:121) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:155) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:310) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) [hibernate-core-5.3.7.Final.jar:5.3.7.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:57) [spring-orm-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) [spring-orm-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:390) [spring-orm-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) [spring-orm-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) [spring-orm-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1804) [spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1741) [spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:576) [spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:498) [spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1083) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:853) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546) ~[spring-context-5.1.4.RELEASE.jar:5.1.4.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]

有人知道如何解决这个问题吗？

Answer 1

将 spring.jpa.hibernate.ddl-auto =创建-拖放更改为更新。它在开始时就删除了数据库，因此找不到所需的事件表来更改任何内容。

Answer 2

在我的情况下，出现此问题的原因是，某些表具有保留给postgreSQL的名称。例如。 “喜欢”或“用户”。更改名称：

@Table(name="likes")

，效果很好。也许有人有同样的问题。

Answer 3

更改hibernate.cfg.xml语言的方言：-org.hibernate.dialect.MySQL5InnoDBDialect 要么 org.hibernate.dialect.MySQL55Dialect 要么 org.hibernate.dialect.MySQL55InnoDBDialect 要么 org.hibernate.dialect.MySQL57InnoDBDialect

Answer 4

只需在您的application.properties中指定方言即可。例如，对于MySQL 8：

hibernate.dialect=org.hibernate.dialect.MySQL8Dialect

Answer 5

嗯，我也遇到了这个问题，但是这些解决方案都不能解决我的问题。我正在将MySQL数据库打包与XAMPP一起使用。我尝试解决的问题但失败了

我删除了位于“ xampp \ mysql \ data”中的数据库
我重命名了有冲突的表
尽管我一开始就保留了该“ spring.jpa.hibernate.ddl-auto = update”设置。

那么我为解决此问题所做的工作。可能是你的

我完全卸载了XAMPP软件包，然后再次安装。
我创建了新的数据库名称
运行应用程序

实际上是我的朋友，也许对您这样的问题有所帮助。如果您有任何疑问，请发表评论。谢谢

Answer 6

遇到类似问题，并在这里找到SupaMario的答案。

在我的情况下，我有一个名为orders的表，但是MySql抛出了错误，因为它似乎是保留表/关键字。

我将其更改为customer_order，并且一切正常。

Answer 7

似乎是与保留的 PostgreSQL单词有关的错误。与最高答案（SupaMario的答案）类似，将我的一个列名从更改为

后，错误消失了

@Column(name = "name", nullable = false)

到

@Column(name = "employee_name", nullable = false)

Answer 8

如果您遇到此问题，请仔细检查您的类属性，以获取诸如key（在我的情况下）之类的保留关键字。

我将密钥更改为mkey，一切正常。

Answer 9

对于使用 PostgreSQL 并且即使您的表名不是关键字也遇到相同问题的任何人，请将以下行放在您的 application.properties 中。它对我有用。

spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true

Answer 10

就我而言，当我在特定实体属性中执行此操作时出现错误

@Column(name ="condition", nullable = false)

我把这个改成

@Column(name ="condition_of_house", nullable = false)

而且效果很好

Answer 11

就我而言，发生错误是因为 mysql 用户没有 REFERENCES 权限。

解决这个问题；

以root用户登录mysql
授予'your_user'@'localhost'的所有权限

或者您只需要授予 'your_user'@'localhost' REFERENCES 权限

查看文档：{{3}}

Answer 12

好的，有同样的问题。添加前缀为我解决了这个问题：

来自：

`
@Entity
@Table(name = "result_man")
@Proxy(lazy = false)
public class ResultManEntity {
@Id
@GeneratedValue
@Column(name = "id", unique = true, length = 128)
private long id;
private String key;
private int score;
private int index;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "result_id")
private ResultEntity result;
}`

收件人：

`@Entity
@Table(name = "result_man")
@Proxy(lazy = false)
public class ResultManEntity {
@Id
@GeneratedValue
@Column(name = "id", unique = true, length = 128)
private long id;
private String _key;
private int _score;
private int _index;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "result_id")
private ResultEntity result;`

Answer 13

就我而言，从数据库中删除表有帮助。但是，请注意，这是一个培训项目:)

如何通过JDBC语句修复“执行DDL错误”（更改表事件会丢弃外键FKg0mkvgsqn8584qoql6a2rxheq）

13 个答案: