石墨烯-django将models.BigInteger()转换为graphene.Integer()

Question

我用的是石墨烯-姜戈。

我试图从models.BigInteger()字段中检索数据，但是当我在graphiQL中进行查询时，我得到了以下错误

{
  "errors": [
    {
      "message": "Int cannot represent non 32-bit signed integer value: 2554208328"
    }
  ],
  "data": {
    "match": null
  }
}

有人知道我怎样才能强迫石墨烯给我数据吗？

Answer 1

我最终使用了一个自定义标量。如果在graphene-django中自动转换为更好的标量会更好，但下面是我如何解决这个问题的。我用定制的BigInt标量编写了一个converter.py文件，如果我们有一个大于MAX_INT的数字，它将使用浮点型而不是整型

# converter.py
from graphene.types import Scalar
from graphql.language import ast
from graphene.types.scalars import MIN_INT, MAX_INT

class BigInt(Scalar):
    """
    BigInt is an extension of the regular Int field
        that supports Integers bigger than a signed
        32-bit integer.
    """
    @staticmethod
    def big_to_float(value):
        num = int(value)
        if num > MAX_INT or num < MIN_INT:
            return float(int(num))
        return num

    serialize = big_to_float
    parse_value = big_to_float

    @staticmethod
    def parse_literal(node):
        if isinstance(node, ast.IntValue):
            num = int(node.value)
            if num > MAX_INT or num < MIN_INT:
                return float(int(num))
            return num

然后

# schema.py
from .converter import BigInt
class MatchType(DjangoObjectType):
    game_id = graphene.Field(BigInt)
    class Meta:
        model = Match
        interfaces = (graphene.Node, )
        filter_fields = {}

Answer 2

您可以注册新的转换器：

    import graphene
    from graphene_django.converter import convert_django_field

    @convert_django_field.register(models.BigIntegerField)
    def convert_bigint_to_float(field, registry=None):
        return graphene.Float(description=field.help_text, required=not field.null)

这就是它在石墨烯中的使用方式-django本身。

Answer 3

这是来自石墨烯的源代码(但我猜还没有发布)：https://github.com/graphql-python/graphene/blob/485b1ed325287fd721b13aac8b4ec872d6295c6a/graphene/types/scalars.py#L85

class BigInt(Scalar):
"""
The `BigInt` scalar type represents non-fractional whole numeric values.
`BigInt` is not constrained to 32-bit like the `Int` type and thus is a less
compatible type.
"""

@staticmethod
def coerce_int(value):
    try:
        num = int(value)
    except ValueError:
        try:
            num = int(float(value))
        except ValueError:
            return None
    return num

serialize = coerce_int
parse_value = coerce_int

@staticmethod
def parse_literal(ast):
    if isinstance(ast, IntValueNode):
        return int(ast.value)

我认为另一个答案中的代码实际上可能更好，但我想链接这个以防万一