Django序列化具有自定义多对多映射的模型

Question

我有三个模型：

class DistinctAlert(models.Model):
    entities = models.ManyToManyField(to='Entity', db_index=True, through='EntityToAlertMap')

class Entity(models.Model):
    entity_instance = models.ManyToManyField(EntityInstance)

class EntityToAlertMap(models.Model):
    entity = models.ForeignKey(Entity, on_delete=models.CASCADE)
    distinct_alert = models.ForeignKey(DistinctAlert, on_delete=models.CASCADE)
    entity_alert_relationship_label = models.ForeignKey(EntityAlertRelationshipLabel, on_delete=models.CASCADE,
                                                        null=True)

除了DistinctAlert和Entity两个额外字段外，我的序列化程序如下：

class EntitySerializer(serializers.ModelSerializer):
    entity_instance = EntityInstanceSerializer(many=True)

    class Meta:
        model = Entity
        fields = ('id', 'entity_instance')

class EntityInstanceSerializer(serializers.ModelSerializer):
    entity_type = EntityTypeSerializer()

    class Meta:
        model = EntityInstance
        fields = ('label', 'entity_type')

class DistinctAlertSerializer(serializers.ModelSerializer):
    entities = EntitySerializer(many=True)

    class Meta:
        model = DistinctAlert
        #TODO how do I serialize custom mapping?
        fields = ('id', 'entities')

我的问题是，使用这个API，它只会返回实体，并且错过了在我用于将实体映射到ManyToMany字段中的不同警报的EntityToAlertMap的“entity_alert_relationship”字段。我的问题是，如何序列化DistinctAlert同时保持实体/关系字段。

- Stupid.Fat.Cat

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看一下这个问题：https://dev59.com/nGQm5IYBdhLWcg3w4CTA。被接受的答案就是你要找的。 - AKS

以上评论中的帖子没有帮助您找到答案吗？ - AKS

Answer 1

您可以为 EntityToAlertMap 编写序列化器。

class EntityToAlertMap(serializers.ModelSerializer):
    class Meta:
        model = EntityToAlertMap
        fields = ('entity', 'distinct_alert', 'entity_alert_relationship_label')

然后你可以通过相关管理器检索所有相关的EntityToAlertMap实例。

class DistinctAlertSerializer(serializers.ModelSerializer):
    entities = EntitySerializer(many=True)
    entity_to_alert_map = EntityToAlertMap(source='entitytoalertmap_set', many=True)

    class Meta:
        model = DistinctAlert
        fields = ('id', 'entities', 'entity_to_alert_map')

- Ivan Semochkin