Cfrgtkky

I have SpringBoot project with Spring Data. Extra column being created when I use the same column name for 2 tables mapped using ManyToOne Relation. I have Address table with column name 'id' and AddressType table with column 'id'. When I start the Spring Boot application with this, I see an extra column (address_id) created on Address table.

Address.java

package com.springtesting.model;



import lombok.Data;



import javax.persistence.*;



@Entity

@Data

@Table(name = "address")

public class Address

{



    @Id

    @GeneratedValue(strategy = GenerationType.AUTO)

    @Column(name = "id")

    private Long id;



    @Column(name = "street_name")

    private String streetName;



    @Column(name = "apartment")

    private String apartment;



    @Column(name = "city")

    private String city;



    @Column(name = "state")

    private String state;



    @Column(name = "country")

    private String country;



    @Column(name = "zip_code")

    private String zipCode;



    @ManyToOne(cascade = CascadeType.ALL)

    @JoinColumn(name = "address_type_id")

    private AddressType addressType;



    public Address()

    {

    }



    public Address(String streetName, String apartment, String city, String state, String country, String zipCode, AddressType addressType)

    {

        this.streetName = streetName;

        this.apartment = apartment;

        this.city = city;

        this.state = state;

        this.country = country;

        this.zipCode = zipCode;

        this.addressType = addressType;

    }

}

and

AddressType.java

package com.springtesting.model;



import lombok.Data;

import lombok.NonNull;



import javax.persistence.*;



@Entity

@Data

@Table(name = "address_type")

public class AddressType

{

    @Id

    @GeneratedValue(strategy = GenerationType.AUTO)

    @Column(name = "id")

    private Long id;



    @Column(name = "type")

    @NonNull

    private String type;



    public AddressType()

    {



    }



    public AddressType(String type)

    {

    }

}

when I start the Spring Boot application, I see extra column (address_id)

Table Structure on Mysql

I'm not sure this will fix your issue, but try changing the @GeneratedValue(strategy = GenerationType.AUTO) to @GeneratedValue(strategy = GenerationType.IDENTITY), or give it a "native" GenericGenerator, as discussed here. Apparently GenerationType.AUTO does not play nice with MySQL from Hibernate 5+.

A couple of other notes:

• You probably don't want to use Lombok's @NonNull, instead just use @Column(name = "type", nullable = false). In fact if the POJO is created through the default constructor, Lombok's @NonNull wouldn't do anything anyway since it's annotated over a field.




• You don't need the cascade = CascadeType.ALL above the AddressType since you probably don't want to accidentally update/delete/or create new AddressTypes through the Address entity. Just annotating it @ManyToOne should be enough.