带有复合主键的表在SpringBoot中的使用

在SpringBoot开发过程中,我们会遇到有些mysql表是带有复合主键的,此时我们进行开发的过程中需要注意以下方面.

1,首先在该表的实例类中的复合主键前面添加如下注解:

@EmbeddedId

比如下面的例子:我的表叫app_network_configs 这个名字,对应的类是:AppNetwork,对应的复合主键是:AppNetworkKey(AppNetworkKey这个单独拎出来使之形成独立的一个类)

@EmbeddedIdprivate AppNetworkKey pk = new AppNetworkKey();

在复合主键的get方法中添加注解:@Transient ,如下的例子:

@Transientpublic App getApp() {    return getPk().getApp();}@Transientpublic Network getNetwork() {    return getPk().getNetwork();}

2,在AppNetworkKey 中我们需要在类的头顶加上这样的注解:@Embeddable

然后后面的就按照正常的方式进行,特别注意,这个类中需要一个空的构造器和含有对应复合主键字段的构造器.

@ManyToOne(fetch = FetchType.LAZY)@JoinColumn(name = "app_id")private App app;@ManyToOne(fetch = FetchType.LAZY)@JoinColumn(name = "network_id")private Network network;public AppNetworkKey() {}public AppNetworkKey(App app, Network network) {    this.app = app;    this.network = network;}
3,使用的例子:
有了上面的表,我们可以做如下的操作:
public interface AppNetworkRepository extends JpaRepository<AppNetwork,AppNetworkKey> {    @Query("select an from AppNetwork an where an.pk.app.id=:appId")    List<AppNetwork> findByAppId(@Param("appId")String appId);    @Query("select an from AppNetwork an where an.pk.network.id=:networkId")    List<AppNetwork> findByNetworkId(@Param("networkId")String networkId);}

附上上面的表对应的实体类
@Entity@Table(name = "app_network_configs")public class AppNetwork implements Serializable {    private static final long serialVersionUID = -5779694190187550788L;    @EmbeddedId    private AppNetworkKey pk = new AppNetworkKey();    private String config;    @Column(name = "config_type")    private String configType;    private Double weight;    @Column(name = "min_ecpm")    private Double minEcpm;    private Boolean available;    @Column(name = "created_at")    private Date createdAt;    @Column(name = "modified_at")    private Date modifiedAt;    private Boolean synced;    @Column(name = "synced_at")    private Date syncedAt;    public AppNetworkKey getPk() {        return pk;    }    public void setPk(AppNetworkKey pk) {        this.pk = pk;    }    @Transient    public App getApp() {        return getPk().getApp();    }    @Transient    public Network getNetwork() {        return getPk().getNetwork();    }    public String getConfig() {        return config;    }    public void setConfig(String config) {        this.config = config;    }    public String getConfigType() {        return configType;    }    public void setConfigType(String configType) {        this.configType = configType;    }    public Double getWeight() {        return weight;    }    public void setWeight(Double weight) {        this.weight = weight;    }    public Double getMinEcpm() {        return minEcpm;    }    public void setMinEcpm(Double minEcpm) {        this.minEcpm = minEcpm;    }    public Boolean getAvailable() {        return available;    }    public void setAvailable(Boolean available) {        this.available = available;    }    public Date getCreatedAt() {        return createdAt;    }    public void setCreatedAt(Date createdAt) {        this.createdAt = createdAt;    }    public Date getModifiedAt() {        return modifiedAt;    }    public void setModifiedAt(Date modifiedAt) {        this.modifiedAt = modifiedAt;    }    public Boolean getSynced() {        return synced;    }    public void setSynced(Boolean synced) {        this.synced = synced;    }    public Date getSyncedAt() {        return syncedAt;    }    public void setSyncedAt(Date syncedAt) {        this.syncedAt = syncedAt;    }}