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) @EmbeddedId private AppNetworkKey pk = new AppNetworkKey(); 在复合主键的get方法中添加注解:@Transient ,如下的例子: @Transient public App getApp() { return getPk().getApp(); } @Transient public 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; } }