2

我继承了以下 JSONField 数据结构：

[
  {
    "name": "Firstname",
    "show": {
      "value": true
    },
    "type": "text",
    "uuid": "55668e45-07d1-404e-bf65-f6a3cacfaa97",
    "label": {
      "for": "Firstname",
      "display": "First name"
    },
    "value": "Michael",
    "options": [],
    "required": true,
    "component": "Input",
    "placeholder": "Input text here",
    "validationErrors": []
  },
  {
    "name": "Surname",
    "show": {
      "value": true
    },
    "type": "text",
    "uuid": "ce91fefa-66e3-4b08-8f1a-64d95771aa49",
    "label": {
      "for": "Surname",
      "display": "Surname"
    },
    "value": "Roberts",
    "options": [],
    "required": true,
    "component": "Input",
    "placeholder": "Input text here",
    "validationErrors": []
  },
  {
    "name": "EmailAddress",
    "show": {
      "value": true
    },
    "type": "email",
    "uuid": "6012a805-da62-4cee-8656-b7565b5f8756",
    "label": {
      "for": "Email",
      "display": "Email"
    },
    "value": "michael@hiyield.co.uk",
    "options": [],
    "required": true,
    "component": "Input",
    "placeholder": "Input text here",
    "validationErrors": []
  },
  {
    "name": "University",
    "show": {
      "value": true
    },
    "type": "text",
    "uuid": "434e3781-ab8a-4f09-9c68-5ec35188f3c7",
    "label": {
      "for": "University",
      "display": "University/College"
    },
    "value": "University College London",
    "options": [],
    "required": true,
    "component": "Input",
    "placeholder": "Input text here",
    "validationErrors": []
  },
  {
    "name": "Subscribe",
    "show": {
      "value": true
    },
    "type": "checkbox",
    "uuid": "79bdc29e-6357-4175-bf65-07be60776a29",
    "label": {
      "for": "Subscribe",
      "display": "Subscribe to the KEVRI mailing list"
    },
    "value": true,
    "options": [],
    "required": true,
    "component": "Checkbox",
    "description": "KEVRI is committed to respecting and protecting your privacy. The data collected here will create your personalised report which we can email to you after this review if you wish. We will not share personal data with anyone else or send you any further emails.",
    "placeholder": "",
    "validationErrors": []
  }
]

存在于models.JSONField中，名为“ about”为“ MyModel”，如下：

class MyModel(
    AbstractTimestampedModel
):

    uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

    about = models.JSONField()

我想知道，我如何过滤MyModel其中的字段about被“名称”调用：“EmailAddress”......然后查询该特定字段“值”？

从本质上讲，对于查询集MyModel.objects.all().filter()......我想过滤掉所有 EmailAddress 等于某个值的值......

我不确定这在 Django ORM 中是否可以实现。但是，可能有人可以建议...

4

2 回答 2

1

如果我是正确的，你应该使用jsonb_to_recordsetPostgreSQL 函数。

首先，您应该创建一个自定义数据库函数，因为 Django Core 中没有该函数。

class JSONRecordSet(Func):
    template = "(SELECT id from %(function)s(%(expressions)s) as items(%(key)s %(output_type)s) where %(key)s='%(search)s')"
    function = "jsonb_to_recordset"

    def __init__(self, expression, key, output_type, search):
        super().__init__(expression, key=key, output_type=output_type, search=search)

请注意 SQL 注入。

之后，您可以将此功能与注释一起使用。

MyModel.objects.annotate(_id=JSONRecordSet(expression="about", key="EmailAddress", output_type="text", search="foo@bar.com")).filter(id=F("_id"))

返回所有在 EmailAddress 键中具有“foo@bar.com”值的 MyModel 实例。

于 2021-10-11T18:06:14.567 回答
0

试试这个方法：

MyModel.objects.filter(about__name='EmailAddress')

它可能会返回您想要的结果。

另外，看看这个链接。它还描述了如何使用 JSONField 查询嵌套字典：

https://docs.djangoproject.com/en/3.2/topics/db/queries/#key-index-and-path-transforms

于 2021-10-12T01:43:22.457 回答