參考鏈接：JPA Primary Key

業(yè)務場景：

實體類Aaabc中需要將id1、id2作為聯(lián)合主鍵來使用

方式一：使用@IdClass

首先定義IdClass類

import lombok.Data;
import java.io.Serializable;

@Data
public class AaabcIdClass implements Serializable {

    private String id1;
    private Integer id2;
}

實體類中指定IdClass，并且使用多個@Id：

import lombok.Data;
import java.io.Serializable;
import javax.persistence.*;
import com.fasterxml.jackson.annotation.JsonInclude;

@Data
@JsonInclude(JsonInclude.Include.NON_NULL)
@Entity
@Table(name = "Aaabc")
@IdClass(AaabcIdClass.class)
public class Aaabc implements Serializable {

    @Id
    @Column(name = "id1", nullable = true, length = 36)
    private String id1;

    @Id
    @Column(name = "id2", nullable = true)
    private Integer id2;

    @Column(name = "name", nullable = true, length = 200)
    private String name;
}

方式二：使用@EmbeddedId與@Embeddable

定義Embeddable類

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import javax.persistence.*;
import java.io.Serializable;


@Data
@AllArgsConstructor
@NoArgsConstructor
@Embeddable
public class AaabcEmbeddedId implements Serializable {
    private String id1;
    private Integer id2;
}

實體類更新為：

import lombok.AllArgsConstructor;
import lombok.Data;
import javax.persistence.*;
import lombok.NoArgsConstructor;

@Entity
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Aaabc {

    @EmbeddedId
    // @AttributeOverrides({@AttributeOverride(name = "id1", column = @Column(name = "id1")), @AttributeOverride(name = "id2", column = @Column(name = "id2"))})
    private AaabcEmbeddedId id12;

    @Column(name = "name", nullable = true, length = 200)
    private String name;
}

持久化實體類對象

public Aaabc saveAaabc() {
        Aaabc bo = new Aaabc();
        // bo.setId1("1");
        // bo.setId2(2);
        bo.setId12(new AaabcEmbeddedId("1", 2));
        bo.setName("name1");
        return aaabcRepository.saveAndFlush(bo);
    }

控制臺輸出：

Hibernate: 
    select
        aaabc0_.id1 as id1_0_0_,
        aaabc0_.id2 as id2_0_0_,
        aaabc0_.name as name3_0_0_ 
    from
        Aaabc aaabc0_ 
    where
        aaabc0_.id1=? 
        and aaabc0_.id2=?
Hibernate: 
    insert 
    into
        Aaabc
        (name, id1, id2) 
    values
        (?, ?, ?)

可見聯(lián)合主鍵生效文章來源地址http://www.zghlxwxcb.cn/news/detail-682129.html

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