英文:
Unable to create a table in hibernate using OneToMany and ManyToOne relationship(also unable to create Foreign Key)
问题
这里的代码主要用于确定OneToMany和ManyToOne的关系。我使用Spring Tool Suite 3.9.11与XAMPP以及Apache 7.5作为服务器。
以下是第一个文件/表customer.java的代码部分：
@Entity
@Table(name = "Customer")
public class Customer {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int cid;
private String cname;
private int ccontact;
private String cemail;
private String cpassword;
@OneToMany(mappedBy = "customer")
private List<OrderF> order;
// 省略了其他方法和构造函数
}
以下是第二个文件/表OrderF.java的代码部分：
@Entity
@Table(name="Order")
public class OrderF {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int food_id;
private String foodName;
@ManyToOne(cascade = CascadeType.PERSIST)
@JoinColumn(name = "cid")
private Customer customer;
// 省略了其他方法和构造函数
}
这是你的main.java的代码部分：
public static void main(String[] args) {
Customer c = new Customer();
c.setCid(1);
OrderF o = new OrderF();
o.setCustomer(c);
o.setFood_id(1);
o.setFoodName("Java");
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();
session.save(o);
session.getTransaction().commit();
session.close();
}
这是你的hibernate配置文件hibernate.cfg.xml的代码部分：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/spring</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password"></property>
<property name="hibernate.show_sql">true</property>
<property name="hbm2ddl.auto">create</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
<mapping class="com.bean.Customer"></mapping>
<mapping class="com.bean.OrderF"></mapping>
</session-factory>
</hibernate-configuration>
这是你的控制台/错误日志部分。
英文:
This code here is simply used to determine the relation of OnetoMany and ManyToOne, I use Spring Tool suite 3.9.11 with XAMPP and Server as apache 7.5
This is first file/table customer.java
package com.bean;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
@Entity
@Table(name = "Customer")
public class Customer {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int cid;
private String cname;
private int ccontact;
private String cemail;
private String cpassword;
@OneToMany(mappedBy = "customer")
private List<OrderF> order;
public List<OrderF> getOrder() {
return order;
}
public void setOrder(List<OrderF> order) {
this.order = order;
}
public Customer() {
super();
}
public int getCid() {
return cid;
}
public void setCid(int cid) {
this.cid = cid;
}
public String getCname() {
return cname;
}
public void setCname(String cname) {
this.cname = cname;
}
public int getCcontact() {
return ccontact;
}
public void setCcontact(int ccontact) {
this.ccontact = ccontact;
}
public String getCemail() {
return cemail;
}
public void setCemail(String cemail) {
this.cemail = cemail;
}
public String getCpassword() {
return cpassword;
}
public void setCpassword(String cpassword) {
this.cpassword = cpassword;
}
}
This is my second file/table OrderF.java
package com.bean;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
@Entity
@Table(name="Order")
public class OrderF {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int food_id;
private String foodName;
@ManyToOne(cascade = CascadeType.PERSIST)
@JoinColumn(name = "cid")
private Customer customer;
public int getFood_id() {
return food_id;
}
public void setFood_id(int food_id) {
this.food_id = food_id;
}
public String getFoodName() {
return foodName;
}
public void setFoodName(String foodName) {
this.foodName = foodName;
}
public Customer getCustomer() {
return customer;
}
public void setCustomer(Customer customer) {
this.customer = customer;
}
}
This is my main.java
package com.bean;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class MainClass {
public static void main(String[] args) {
Customer c=new Customer();
c.setCid(1);
OrderF o=new OrderF();
o.setCustomer(c);
o.setFood_id(1);
o.setFoodName("Java");
SessionFactory sessionFactory=new Configuration().configure().buildSessionFactory();
Session session=sessionFactory.openSession();
session.beginTransaction();
session.save(o);
session.getTransaction().commit();
session.close();
}
}
This is hibernate Configuration file hibernate.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/spring</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password"></property>
<property name="hibernate.show_sql">true</property>
<property name="hbm2ddl.auto">create</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
<mapping class="com.bean.Customer"></mapping>
<mapping class="com.bean.OrderF"></mapping>
</session-factory>
</hibernate-configuration>
This is my Console/Error Log:
version for the right syntax to use near 'Order drop foreign key FKk8oprs3d23xg7tjw95wxaft8l' at line 1
Hibernate: drop table if exists Customer
Hibernate: drop table if exists Order
Aug 14, 2020 12:04:34 PM org.hibernate.tool.hbm2ddl.SchemaExport perform
ERROR: HHH000389: Unsuccessful: drop table if exists Order
Hibernate: create table Customer (cid integer not null auto_increment, ccontact integer not null, cemail varchar(255), cname varchar(255), cpassword varchar(255), primary key (cid))
Aug 14, 2020 12:04:34 PM org.hibernate.tool.hbm2ddl.SchemaExport perform
ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'Order' at line 1
Hibernate: create table Order (food_id integer not null auto_increment, foodName varchar(255), cid integer, primary key (food_id))
Aug 14, 2020 12:04:35 PM org.hibernate.tool.hbm2ddl.SchemaExport perform
ERROR: HHH000389: Unsuccessful: create table Order (food_id integer not null auto_increment, foodName varchar(255), cid integer, primary key (food_id))
Hibernate: alter table Order add constraint FKk8oprs3d23xg7tjw95wxaft8l foreign key (cid) references Customer (cid)
Aug 14, 2020 12:04:35 PM org.hibernate.tool.hbm2ddl.SchemaExport perform
ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'Order (food_id integer not null auto_increment, foodName varchar(255), cid integ' at line 1
Aug 14, 2020 12:04:35 PM org.hibernate.tool.hbm2ddl.SchemaExport perform
ERROR: HHH000389: Unsuccessful: alter table Order add constraint FKk8oprs3d23xg7tjw95wxaft8l foreign key (cid) references Customer (cid)
Aug 14, 2020 12:04:35 PM org.hibernate.tool.hbm2ddl.SchemaExport perform
ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'Order add constraint FKk8oprs3d23xg7tjw95wxaft8l foreign key (cid) references Cu' at line 1
Aug 14, 2020 12:04:35 PM org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: HHH000230: Schema export complete
Hibernate: insert into Order (cid, foodName) values (?, ?)
Aug 14, 2020 12:04:35 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
WARN: SQL Error: 1064, SQLState: 42000
Aug 14, 2020 12:04:35 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'Order (cid, foodName) values (1, 'Java')' at line 1
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not execute statement
at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:106)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:109)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:95)
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:207)
at org.hibernate.dialect.identity.GetGeneratedKeysDelegate.executeAndExtract(GetGeneratedKeysDelegate.java:57)
at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:42)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2792)
at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3363)
at org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
at org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:597)
at org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:232)
at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:213)
at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:256)
at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:317)
at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:272)
at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:178)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:109)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:679)
答案1
得分: 0
您的Order实体的表名是SQL引擎中的保留字，尝试重新命名表名。
@Entity
@Table(name="OrderF")
public class OrderF {...}
英文:
Your Order entity's table name is a reserved word in the SQL engine, try renaming the table's name
@Entity
@Table(name="OrderF ")
public class OrderF {...}
答案2
得分: 0
作为重命名的替代方法，您可以使用SQL带引号的标识符:
@Entity
@Table(name="`Order`")
public class OrderF {
// ...
}
英文:
As an alternative to renaming you can use SQL quoted identifiers:
@Entity
@Table(name="`Order`")
public class OrderF {
// ...
}
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