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问题

你好,

我在 Python 3.7 中使用 Graphene Django 和 Graphene Relay。我正在尝试使用 Django 过滤器为 GraphQL 中的请求制作自定义过滤器。

我的表如下所示:

| id(type: int) | flow(type: varchar) | datetime(type: datetime) | duration(type: int) |
|---------------|---------------------|--------------------------|---------------------|
| 1             | aaa                 | 2019-07-06 08:59:00      | 113095465           |
| 2             | xxx                 | 2019-07-06 08:59:00      | 113095465           |
| 3             | bbb                 | 2019-07-06 08:59:00      | 113095465           |

我希望能够使用 GraphQL 执行这种 SQL 请求:

SELECT * FROM tablename WHERE datetime <= "2019-07-06 09:00:00" AND DATE_ADD(datetime, INTERVAL duration / 1000 SECOND) >= "2019-07-06 08:59:00";

使用 graphql 查询,例如:(当然日期将采用 Python DateTime 格式)

{
  allTable(startDate: "2019-07-06 08:59:00", endDate: "2019-07-06 09:00:00") {
    edges {
      node {
        id
        name
      }
    }
  }
}

像这样也可以,只要它有效:

{
  allTable(timeRange: "{'start':'2019-07-06 08:59:00', 'end': '2019-07-06 09:00:00'}") {
    edges {
      node {
        id
        name
      }
    }
  }
}

代码

models.py

from django.db import models

class TableName(models.Model):
    name = models.CharField()
    datetime = models.DateTimeField()
    duration = models.BigIntegerField()
    class Meta:
        managed = False
        db_table = 'tablename'

schema.py

from graphene import relay, ObjectType
from graphene_django import DjangoObjectType
from graphene_django.filter import DjangoFilterConnectionField
import django_filters

from .models import TableName
from .fieldList import fields_table

class TableFilter(django_filters.FilterSet):
    class Meta:
        model = TableName
        fields = fields_table

class TableType(DjangoObjectType):
    class Meta:
        model = TableName
        filterset_class = TableFilter
        interfaces = (relay.Node,)

class Query(ObjectType):
    table = relay.Node.Field(TableType)
    all_Table = DjangoFilterConnectionField(TableType)

我已经设法在字段上添加自定义过滤器并在 GraphQL 中获取此过滤器:

class TableFilter(django_filters.FilterSet):
    yolo = django_filters.NumberFilter(field_name="duration", lookup_expr='gt')
    ...

但我不知道如何添加这种类型的自定义过滤器。

到目前为止,我已经看过这些文档:django_filters 文档石墨烯文档Django 文档关于查询集,但无法理解所有内容,也找不到符合我需要的示例:/

感谢您花时间提供帮助:)

解决方案(未优化)

我最终使用它来获得我想要的东西,但它没有优化,因为我无法获得DjangoFilterConnectionField.

如果您有更好的解决方案,我很乐意接受,因为分页和过滤器很好!

schema.py

from graphene import relay, ObjectType, List
from graphene_django import DjangoObjectType
from graphene_django.filter import DjangoFilterConnectionField
import django_filters
import graphene

from .models import TableName
from .fieldList import fields_table

class TableFilter(django_filters.FilterSet):
    class Meta:
        model = TableName
        fields = fields_table

class TableType(DjangoObjectType):
    class Meta:
        model = TableName
        filterset_class = TableFilter
        interfaces = (relay.Node,)

class Query(ObjectType):
    table = relay.Node.Field(TableType)
    all_Table = DjangoFilterConnectionField(TableType)
    table_range = List(TableType, startDate=graphene.Argument(
        graphene.DateTime, required=True), endDate=graphene.Argument(graphene.DateTime, required=True))

    def resolve_trace_range(root, info, startDate, endDate):
        return TableType.objects.raw("""
        SELECT * FROM tablename WHERE
        datetime <= '{}'
        AND DATE_ADD(datetime, INTERVAL duration / 1000 SECOND) >= '{}';
        """.format(str(startDate), str(endDate)))

这使我可以执行以下请求:

{
  tableRange(startDate: "2019-08-19T08:31:24.315Z", endDate: "2019-08-19T09:31:24.315Z") {
      id
      flow
      datetime
      duration
  }
}

请注意, DateTime 使用ISO-8601进行格式化。在 javascript 中,您可以使用以下方法获取它:

now = new Date().toISOString();
console.log(now); 
// Output: 2019-08-19T09:34:19.075Z
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