Java Hibernate 不会自动创建表
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Hibernate doesn't create tables automatically
提问by Egorika Belarus
I have Maven project with Hibernate/Spring/MySQL. I have basic entity and I want Hibernate to create tables automatically, but Hibernate doesn't create any tables. No exceptions are thrown too, so I have no idea what is wrong here.
我有一个带有 Hibernate/Spring/MySQL 的 Maven 项目。我有基本实体，我希望 Hibernate 自动创建表，但 Hibernate 不创建任何表。也没有抛出异常，所以我不知道这里出了什么问题。
application.properties:
应用程序属性：
# ===============================
# = DATA SOURCE
# ===============================
spring.datasource.url = jdbc:mysql://localhost:3306/task
spring.datasource.username = root
spring.datasource.password = 12345678
spring.datasource.testWhileIdle = true
spring.datasource.validationQuery = SELECT 1
# ===============================
# = JPA / HIBERNATE
# ===============================
spring.jpa.show-sql = true
spring.jpa.hibernate.ddl-auto = create
spring.jpa.hibernate.naming-strategy = org.hibernate.cfg.ImprovedNamingStrategy
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQLDialect
spring.datasource.driver-class-name = com.mysql.jdbc.Driver
spring.jpa.properties.hibernate.format_sql = true
spring.jpa.properties.hibernate.id.new_generator_mappings = true
logging.level.org.hibernate.SQL=DEBUG
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE
spring.datasource.tomcat.max-wait=20000
spring.datasource.tomcat.max-active=50
spring.datasource.tomcat.max-idle=20
spring.datasource.tomcat.min-idle=15
spring.datasource.tomcat.test-while-idle=true
spring.datasource.tomcat.test-on-borrow=true
spring.datasource.tomcat.time-between-eviction-runs-millis=3600000
spring.datasource.tomcat.validation-query=SELECT 1
User.java:
用户.java：
package com.example.model;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import lombok.Data;
@Entity
@Table(name = "user")
@Data
public class User {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "id")
private int id;
@Column(name = "telegramId")
private Integer telegramId;
@Column(name = "firstName")
private String firstName;
@Column(name = "lastName")
private String lastName;
@OneToMany(
mappedBy = "user",
cascade = CascadeType.ALL,
orphanRemoval = true
)
private List<Message> msg = new ArrayList<>();
}
In User.java I also use lombok. Any suggestions? Thank you.
在 User.java 我也使用 lombok。有什么建议？谢谢你。
采纳答案by Egorika Belarus
I found a solution. The problem was that Application.java was in package com.example.BotApp., now it's in com.example.. I don't know, but somehow it helped.
我找到了解决方案。问题是 Application.java 在 package 中com.example.BotApp.，现在在com.example.. 我不知道，但不知何故它有所帮助。
回答by paardhu
you are missing this property in your properties file
您的属性文件中缺少此属性
hibernate.hbm2ddl.auto="update"
hibernate.hbm2ddl.auto="更新"
spring.jpa.properties.hibernate.hbm2ddl.auto=update
hibernate.hbm2ddl.auto is automatically validates and exports DDL to schema when the sessionFactory is created.
hibernate.hbm2ddl.auto 在 sessionFactory 创建时自动验证并将 DDL 导出到模式。
By default, It is not doing any creation or modification automatically on db. If user sets values to update or create or validate or create-dropthen it is doing DDL schema changes automatically according to given value.
默认情况下，它不会自动对 db 进行任何创建或修改。如果用户将值设置为更新或创建或验证或创建删除，则它会根据给定值自动执行 DDL 模式更改。
回答by Urosh T.
If you are using spring-data(which I hope you are), remove the @Tableannotation, Spring will automatically create a table with the name userjust from the @Entity. The minimum config that should go inside your application.propertesis this:
如果您正在使用spring-data（我希望您是这样），请删除@Table注释，Spring 将自动创建一个名为user的表，仅从@Entity. 应该进入你的最低配置application.propertes是这样的：
# Hibernate
spring.datasource.platform=mysql
spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.hibernate.ddl-auto=update
# Mysql
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://yourdburl:3306/test?createDatabaseIfNotExist=true // creates a schema if doesn't exist
spring.datasource.username=root
spring.datasource.password=12345678
spring.jpa.hibernate.ddl-auto=updatewill update your DB table (if necessary) every time your app connects to it. It should also create it if there is none.
Other values are
createand create-dropwhich are pretty much self-explanatory
spring.jpa.hibernate.ddl-auto=update每次您的应用程序连接到它时都会更新您的数据库表（如有必要）。如果没有，它也应该创建它。其他值是
create和create-drop几乎不言自明
回答by Diego Santa Cruz Mendezú
test changing the name of the table, this worked for me.
测试更改表的名称，这对我有用。
回答by Paulo
in my case, I believe that, because I was using hibernate 5, hibernate 5 should solve some format problems for the columns table automatically, some tables were not created, but others were. I DIFF the files to analyze the differences...and the problem was... I was using a property and that impeded the creating of the table...
就我而言，我相信，因为我使用的是 hibernate 5，所以 hibernate 5 应该自动解决列表的一些格式问题，有些表没有创建，但其他表是。我 DIFF 文件以分析差异......问题是......我正在使用一个属性并且阻碍了表格的创建......
@Column(nullable = false, columnDefinition = "DECIMAL(6,6) DEFAULT 0.00")
private Double longitude;
I've deleted columnDefinition = "DECIMAL(6,6) DEFAULT 0.00", and the tables were created normally.
我已经删除了columnDefinition = "DECIMAL(6,6) DEFAULT 0.00"，并且表已正常创建。
