java - 使用 PostgreSQL 和 Spring Boot 时是否有规则禁止将其实体类命名为 "User"？

标签 java postgresql hibernate spring-boot jpa

伙计们。我在 Spring boot 2.3.0 和 PostgreSQL 12 项目中遇到问题。我有一个名为 User 的实体类，其代码如下:

@Entity
@NoArgsConstructor
@Data
@AllArgsConstructor
@Builder
public class User {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String username;
    private String email;
    private String firstName;
    private String lastName;
    private int age;
}

我的 application.properties 文件如下所示:

spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.hibernate.show-sql=true
spring.datasource.url=jdbc:postgresql://localhost:5432/dbname
spring.datasource.username=postgres
spring.datasource.password=*********

令人担忧的是，当我执行项目时，我会遇到这样的错误:

org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "drop table if exists user cascade" via JDBC Statement
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) ~[hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:375) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:359) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:241) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:154) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:126) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:112) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:145) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:73) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:314) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:468) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1249) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) [spring-orm-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) [spring-orm-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:391) [spring-orm-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_252]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_252]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_252]
    at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_252]
Caused by: org.postgresql.util.PSQLException: ERREUR: erreur de syntaxe sur ou près de « user »
  Position : 22
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2533) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2268) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:313) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:448) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:369) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:310) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeCachedSql(PgStatement.java:296) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:273) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:268) ~[postgresql-42.2.12.jar:42.2.12]
    at com.zaxxer.hikari.pool.ProxyStatement.execute(ProxyStatement.java:95) ~[HikariCP-3.4.5.jar:na]
    at com.zaxxer.hikari.pool.HikariProxyStatement.execute(HikariProxyStatement.java) ~[HikariCP-3.4.5.jar:na]
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ~[hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    ... 18 common frames omitted

2020-05-24 06:16:33.429  WARN 13636 --- [         task-1] o.h.t.s.i.ExceptionHandlerLoggedImpl     : GenerationTarget encountered exception accepting command : Error executing DDL "create table user (id int8 generated by default as identity, age int4 not null, email varchar(255), first_name varchar(255), last_name varchar(255), username varchar(255), primary key (id))" via JDBC Statement

org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL "create table user (id int8 generated by default as identity, age int4 not null, email varchar(255), first_name varchar(255), last_name varchar(255), username varchar(255), primary key (id))" via JDBC Statement
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) ~[hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:439) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:423) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:314) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:166) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:135) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:121) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:156) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:73) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:314) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:468) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1249) [hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) [spring-orm-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) [spring-orm-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:391) [spring-orm-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_252]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_252]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_252]
    at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_252]
Caused by: org.postgresql.util.PSQLException: ERREUR: erreur de syntaxe sur ou près de « user »
  Position : 14
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2533) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2268) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:313) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:448) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:369) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:310) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeCachedSql(PgStatement.java:296) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:273) ~[postgresql-42.2.12.jar:42.2.12]
    at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:268) ~[postgresql-42.2.12.jar:42.2.12]
    at com.zaxxer.hikari.pool.ProxyStatement.execute(ProxyStatement.java:95) ~[HikariCP-3.4.5.jar:na]
    at com.zaxxer.hikari.pool.HikariProxyStatement.execute(HikariProxyStatement.java) ~[HikariCP-3.4.5.jar:na]
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ~[hibernate-core-5.4.15.Final.jar:5.4.15.Final]
    ... 18 common frames omitted

但是，当我更改类(class)名称时，例如至人

@Entity
@NoArgsConstructor
@Data
@AllArgsConstructor
@Builder
public class Person {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String username;
    private String email;
    private String firstName;
    private String lastName;
    private int age;
}

我没有收到任何错误。有人可以通过以下方式帮助我解决这个问题，或者至少向我解释实体类 User 有什么问题。 我还想补充一点，当有疑问时，我使用 MySQL 作为 PostgreSQL 的替代品测试了这段代码，没有出现任何错误。

最佳答案

在 PostgreSQL 中 user 是保留关键字。使用 @Table

使用像 "user" 这样的引号作为表名 
@Table(name = "\"user\"")
public class User {

表名的更好命名是使用复数形式，例如users。

@Table(name = "users")
public class User {

关于java - 使用 PostgreSQL 和 Spring Boot 时是否有规则禁止将其实体类命名为 "User"？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/61981787/

上一篇：java - 当应用程序在前台运行时使用挂起 Intent 或其他解决方案从主菜单打开特定选项卡

下一篇：java - 如何以当前毫秒为单位检查 1 天摘要的数据库记录

相关文章：

java - 在我的事务中获取 org.hibernate.NonUniqueObjectException

java - Hibernate xml 列定义

java - 在我的 GUI (java) 中显示 CMD 输出

java - 在java中将字符串转换为日期时间

java - 在java中从数组中查找最小值

python-3.x - 使用 sslmode 运行 postgres 连接字符串(用于 SQLAlchemy)时出现 Docker 错误

postgresql - EJB3.1 注入(inject) JSF2.1 托管 bean 的不确定行为

java - JSF 表单不执行操作，因为组合框

sql - 检查 JSON 数组中是否存在值

java - hibernate java ORA-02292 : integrity constraint violated - child record found Course with Review

©2024 IT工具网  联系我们