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[英]spring boot: hibernate cannot mapping entity to table in postgresql: spring boot
[英]Table Column Mapping error on Hibernate with spring boot
我在MySql数据库上有两个表。 与Item.groupid -> ItemGroup.id
相关的Item,ItemGroup我也使用了hibernate-entitymanager
和spring boot。 这是我的Item和ItemGroup实体类。
Item.java
package com.thiha.entities;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
@Entity
public class Item {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
private String createdDate;
private String modifiedDate;
private String itemCode;
private String description;
private int groupId;
private double quantity;
private double price;
private int recordStatus;
private ItemGroup itemGroup;
@ManyToOne
@JoinColumn(name = "groupid")
public ItemGroup getItemGroup() {
return itemGroup;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getCreatedDate() {
return createdDate;
}
public void setCreatedDate(String createdDate) {
this.createdDate = createdDate;
}
public String getModifiedDate() {
return modifiedDate;
}
public void setModifiedDate(String modifiedDate) {
this.modifiedDate = modifiedDate;
}
public String getItemCode() {
return itemCode;
}
public void setItemCode(String itemCode) {
this.itemCode = itemCode;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public int getGroupId() {
return groupId;
}
public void setGroupId(int groupId) {
this.groupId = groupId;
}
public double getQuantity() {
return quantity;
}
public void setQuantity(double quantity) {
this.quantity = quantity;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public int getRecordStatus() {
return recordStatus;
}
public void setRecordStatus(int recordStatus) {
this.recordStatus = recordStatus;
}
}
ItemGroup.java
package com.thiha.entities;
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.OneToMany;
@Entity
public class ItemGroup {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
private String createdDate;
private String modifiedDate;
private String groupCode;
private String groupName;
private int recordStatus;
private List<Item> items;
@OneToMany(mappedBy = "itemGroup", cascade = CascadeType.ALL)
public List<Item> getItems(){
return items;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getCreatedDate() {
return createdDate;
}
public void setCreatedDate(String createdDate) {
this.createdDate = createdDate;
}
public String getModifiedDate() {
return modifiedDate;
}
public void setModifiedDate(String modifiedDate) {
this.modifiedDate = modifiedDate;
}
public String getGroupCode() {
return groupCode;
}
public void setGroupCode(String groupCode) {
this.groupCode = groupCode;
}
public String getGroupName() {
return groupName;
}
public void setGroupName(String groupName) {
this.groupName = groupName;
}
public int getRecordStatus() {
return recordStatus;
}
public void setRecordStatus(int recordStatus) {
this.recordStatus = recordStatus;
}
}
我还使用带外键groupid的ItemTable引用在Item表中创建了一个外键。 但是当我使用mvn spring-boot:run
代码时,出现了如下异常:
org.hibernate.MappingException: Could not determine type for: java.util.List, at table: item_group, for columns: [org.hibernate.mapping.Column(items)]
at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:431)
at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:398)
at org.hibernate.mapping.Property.isValid(Property.java:225)
at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:595)
at org.hibernate.mapping.RootClass.validate(RootClass.java:265)
at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:329)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:443)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:879)
如果我在两个类中都删除了关系,则它可以正常工作,但无法进行INNER JOIN
查询。 请帮我解决这个问题
您不能在Hibernate中混合使用注释约定。 请尝试将@Id
和@GeneratedValue
批注移至getter,或将@OneToMany
和@ManyToOne
移至字段。
它说
无法确定类型:java.util.List,在表:item_group中,对于列:[org.hibernate.mapping.Column(items)]'
因为您的mappedBy
不正确。
当在getter getCategory()
上添加注释时,hibernate会理解它为category
。
@ManyToOne
@JoinColumn(name = "groupid")
public ItemGroup getCategory() {
return itemGroup;
}
因此,请在您的class ItemGroup
使用适当的名称
@OneToMany(mappedBy = "category", cascade = CascadeType.ALL)
public List<Item> getItems(){
return items;
}
不用担心,只有一件事可以删除ID上的@Id和@generatorValue注释,然后将其放在getter方法上,问题将得到解决.....!
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