Spring JPA如何将外键关联到目标实体嵌入式主键的指定字段

LeagueTeam使用了复合嵌入式主键（由code和name两个字段组成），当你在PlayerBasicInformation中用@ManyToOne关联LeagueTeam时，JPA要求外键必须匹配复合主键的所有列，但你只配置了TEAM_CODE对应code字段，缺少对应name字段的外键列，因此触发了映射异常。

根据业务场景，提供两种可行方案：

方案一：调整主键设计（推荐） #

观察到LeagueTeamPrimaryKey中的code字段已经标记为unique = true，说明code本身是唯一的，完全可以作为单独的主键，无需使用复合主键。这种方式能简化关联配置，避免复合主键带来的复杂度：

1. 修改LeagueTeam实体类：

@Entity
@DynamicUpdate
@Table(name = "LEAGUE_TEAM")
public class LeagueTeam {

    @Id
    @Column(unique = true, updatable = false)
    private int code;
    
    @Column(length = 30, updatable = false)
    private String name;
    
    // 保留原有其他字段
    private int draw;
    private float form;
    private int loss;
    private int played;
    private int points;
    private int position;
    @Column(name = "SHRT_NAME", length = 3)
    private String shortName;
    @Column(name = "STRGTH")
    private int strength;
    @Column(name = "TEAM_DIV", length = 10)
    private String teamDivision;
    @Column(name = "UN_AVLBL")
    private boolean unavailable;
    private int win;
    @Column(name = "STRGTH_OVR_HOME")
    private int strengthOverallHome;
    @Column(name = "STRGTH_OVR_AWAY")
    private int strengthOverallAway;
    @Column(name = "STRGTH_ATT_HOME")
    private int strengthAttackHome;
    @Column(name = "STRGTH_ATT_AWAY")
    private int strengthAttackAway;
    @Column(name = "STRGTH_DEF_HOME")
    private int strengthDefenceHome;
    @Column(name = "STRGTH_DEF_AWAY")
    private int strengthDefenceAway;
    @Column(name = "PULSE_ID")
    private int pulseId;
}

2. 删除LeagueTeamPrimaryKey类，无需再使用嵌入式主键。

3. PlayerBasicInformation的关联配置保持不变即可正常工作：

@ManyToOne(optional = false)
@JoinColumn(name = "TEAM_CODE", referencedColumnName = "CODE")
private LeagueTeam teamCode;

方案二：保留复合主键，添加完整外键列 #

如果业务上必须保留复合主键，那么需要在PlayerBasicInformation的数据库表中添加对应name字段的外键列，并配置完整的关联映射：

修改PlayerBasicInformation实体类：

@Entity
@Table(name = "PLYR_BSC_INFO")
public class PlayerBasicInformation {

    @Id
    private Long code;
    @Column(name = "FRST_NAME")
    private String firstName;
    @Column(name = "SECD_NAME")
    private String secondName;
    @Column(name = "SQD_NO")
    private Integer squadNumber;
    @Column(name = "PLYR_STS")
    private Character status;
    
    // 配置对应复合主键的两个外键列
    @ManyToOne(optional = false)
    @JoinColumns({
        @JoinColumn(name = "TEAM_CODE", referencedColumnName = "CODE"),
        @JoinColumn(name = "TEAM_NAME", referencedColumnName = "NAME")
    })
    private LeagueTeam team;
    
    @Column(name = "WEB_NAME")
    private String webName;
}

同时需要确保数据库表PLYR_BSC_INFO存在TEAM_NAME列，与LEAGUE_TEAM表的NAME列类型匹配。

内容的提问来源于stack exchange，提问作者Rohan Aditeya