spring - 休眠和堆栈跟踪的 Spring Data JPA 问题
问题描述
我在 amigoscode.com 上关注 Spring Data JPA 课程，但遇到了一个问题。我正在创建一个小型 JPA 应用程序，但遇到以下问题。为了确保这一点，我从讲师的 GitHub 上查看了代码并运行了该代码并遇到了完全相同的问题。所以，这里是：
该应用程序具有两个类 Student 和 StudentIdCard 的存储库以及具有 main 方法的应用程序类以及所有这些。在那个类中，我们返回一个作为 CommandLineRunner 的 Bean。
这是两个类：
package com.example.demo;
import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;
@Entity(name = "Student")
@Table(
name = "student",
uniqueConstraints = {
@UniqueConstraint(name = "student_email_unique", columnNames = "email")
}
)
public class Student {
@Id
@SequenceGenerator(
name = "student_sequence",
sequenceName = "student_sequence",
allocationSize = 1
)
@GeneratedValue(
strategy = GenerationType.SEQUENCE,
generator = "student_sequence"
)
@Column(
name = "id",
updatable = false
)
private Long id;
@Column(
name = "first_name",
nullable = false,
columnDefinition = "TEXT"
)
private String firstName;
@Column(
name = "last_name",
nullable = false,
columnDefinition = "TEXT"
)
private String lastName;
@Column(
name = "email",
nullable = false,
columnDefinition = "TEXT"
)
private String email;
@Column(
name = "age",
nullable = false
)
private Integer age;
@OneToOne(
mappedBy = "student",
orphanRemoval = true
)
private StudentIdCard studentIdCard;
public Student(String firstName,
String lastName,
String email,
Integer age) {
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
this.age = age;
}
public Student() {
}
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 Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", first_name='" + firstName + '\'' +
", last_name='" + lastName + '\'' +
", email='" + email + '\'' +
", age=" + age +
'}';
}
}
package com.example.demo;
import javax.persistence.*;
@Entity(name = "StudentIdCard")
@Table(
name = "student_id_card",
uniqueConstraints = {
@UniqueConstraint(
name = "student_id_card_number_unique",
columnNames = "card_number"
)
}
)
public class StudentIdCard {
@Id
@SequenceGenerator(
name = "student_id_card_sequence",
sequenceName = "student_id_card_sequence",
allocationSize = 1
)
@GeneratedValue(
strategy = GenerationType.SEQUENCE,
generator = "student_id_card_sequence"
)
@Column(
name = "id",
updatable = false
)
private Long id;
@Column(
name = "card_number",
nullable = false,
length = 15
)
private String cardNumber;
@OneToOne(
cascade = CascadeType.ALL
)
@JoinColumn(
name = "student_id",
nullable = false,
referencedColumnName = "id",
foreignKey = @ForeignKey(
name = "student_id_fkey"
)
)
private Student student;
public StudentIdCard() {
}
public StudentIdCard(Long id, String cardNumber) {
this.id = id;
this.cardNumber = cardNumber;
}
public StudentIdCard(String cardNumber, Student student) {
this.cardNumber = cardNumber;
this.student = student;
}
public Long getId() {
return id;
}
public String getCardNumber() {
return cardNumber;
}
@Override
public String toString() {
return "StudentIdCard{" +
"id=" + id +
", cardNumber='" + cardNumber + '\'' +
", student=" + student +
'}';
}
}
这是命令行运行程序：
@Bean
CommandLineRunner commandLineRunner(StudentRepository studentRepository, StudentIdCardRepository studentIdCardRepository) {
return args -> {
Faker faker = new Faker();
String firstName = faker.name().firstName();
String lastName = faker.name().lastName();
String email = String.format("%s.%s@amigoscode.com", firstName, lastName);
Student student = new Student(firstName, lastName, email, faker.number().numberBetween(17, 55));
StudentIdCard studentIdCard = new StudentIdCard("123456789", student);
studentIdCardRepository.save(studentIdCard);
studentRepository.findById(1L).ifPresent(System.out::println);
studentIdCardRepository.findById(1L).
ifPresentOrElse(System.out::println,
() -> {
System.out.println("Student with id 1 does not exist!");
});
等等等等
当我运行代码时，有两件事出错了。服务器启动并执行所有操作。但是语句 studentRepository.findById(1L) （是的，我们知道学生的 id 为 1）我们也应该得到 studentIdCard，因为我们与在学生类中映射的 studentIdCard 有一对一的关系。根据控制台中的 Hibernate 输出，它应该可以工作，但不能：
Hibernate:
select
student0_.id as id1_1_0_,
student0_.age as age2_1_0_,
student0_.email as email3_1_0_,
student0_.first_name as first_na4_1_0_,
student0_.last_name as last_nam5_1_0_,
studentidc1_.id as id1_2_1_,
studentidc1_.card_number as card_num2_2_1_,
studentidc1_.student_id as student_3_2_1_
from
student student0_
left outer join
student_id_card studentidc1_
on student0_.id=studentidc1_.student_id
where
student0_.id=?
Student{id=1, first_name='Shamika', last_name='Treutel', email='Shamika.Treutel@amigoscode.com', age=24}
结果中只显示了学生列。这是为什么？
另外，第二个问题是，即使在我们走到这一步之前，我总是得到一个我不理解的奇怪堆栈跟踪（不理解 DDL）。它不会影响服务器的工作，但我认为这是不对的。我从 IntelliJ 运行了讲师的 repo，它给出了相同的堆栈跟踪。
堆栈跟踪：
Hibernate:
alter table book
drop constraint student_book_fkey
2021-06-26 18:06:18.391 WARN 42876 --- [ main] o.h.t.s.i.ExceptionHandlerLoggedImpl : GenerationTarget encountered exception accepting command : Error executing DDL "
alter table book
drop constraint student_book_fkey" via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "
alter table book
drop constraint student_book_fkey" via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:375) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:359) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applyConstraintDropping(SchemaDropperImpl.java:331) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:230) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:154) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:126) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:112) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:145) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:73) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:318) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:468) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1259) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1845) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.8.jar:5.3.8]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.8.jar:5.3.8]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.8.jar:5.3.8]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.2.jar:2.5.2]
at com.example.demo.DemoApplication.main(DemoApplication.java:18) ~[classes/:na]
Caused by: org.postgresql.util.PSQLException: ERROR: relation "book" does not exist
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2552) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2284) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:322) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:481) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:401) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:322) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeCachedSql(PgStatement.java:308) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:284) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:279) ~[postgresql-42.2.22.jar:42.2.22]
at com.zaxxer.hikari.pool.ProxyStatement.execute(ProxyStatement.java:94) ~[HikariCP-4.0.3.jar:na]
at com.zaxxer.hikari.pool.HikariProxyStatement.execute(HikariProxyStatement.java) ~[HikariCP-4.0.3.jar:na]
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
... 35 common frames omitted
休眠：
alter table student_id_card
drop constraint student_id_fkey
2021-06-26 18:06:18.393 WARN 42876 --- [ main] o.h.t.s.i.ExceptionHandlerLoggedImpl : GenerationTarget encountered exception accepting command : Error executing DDL "
alter table student_id_card
drop constraint student_id_fkey" via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "
alter table student_id_card
drop constraint student_id_fkey" via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:375) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:359) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.applyConstraintDropping(SchemaDropperImpl.java:331) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:230) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:154) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:126) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:112) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:145) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:73) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:318) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:468) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1259) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1845) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.8.jar:5.3.8]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.8.jar:5.3.8]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.8.jar:5.3.8]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.8.jar:5.3.8]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.2.jar:2.5.2]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.2.jar:2.5.2]
at com.example.demo.DemoApplication.main(DemoApplication.java:18) ~[classes/:na]
Caused by: org.postgresql.util.PSQLException: ERROR: relation "student_id_card" does not exist
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2552) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2284) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:322) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:481) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:401) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:322) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeCachedSql(PgStatement.java:308) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:284) ~[postgresql-42.2.22.jar:42.2.22]
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:279) ~[postgresql-42.2.22.jar:42.2.22]
at com.zaxxer.hikari.pool.ProxyStatement.execute(ProxyStatement.java:94) ~[HikariCP-4.0.3.jar:na]
at com.zaxxer.hikari.pool.HikariProxyStatement.execute(HikariProxyStatement.java) ~[HikariCP-4.0.3.jar:na]
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ~[hibernate-core-5.4.32.Final.jar:5.4.32.Final]
... 35 common frames omitted
解决方案
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