2

我正在获取基于 specific 的文档EmbeddedDocument，但我不想在检索的同时获取所有文档，只获取与 mainEmbeddedDocuments匹配的文档。EmbeddedDocumentDocument

这是我的代码：

学校嵌入式文档

class School(EmbeddedDocument):
    name = StringField(max_length=120)

用户文件

class User(Document):
    first_name = StringField(max_length=60, required=True)
    last_name = StringField(max_length=60)
    schools = EmbeddedDocumentListField(School)

进给文件：

user = User.objects.create(first_name="Rohit", last_name="Khatri")
user.schools = [
    School(name="Auden High School")),
    School(name="Baldwin Boys High School"),
    School(name="Baldwin Girls High School"),
    School(name="Aukamm Elementary School"),
    School(name="Mason-Rice Elementary")
]
user.save()

user = User.objects.create(first_name="ABC", last_name="DEF")
user.schools = [
    School(name="Little Harbor Elementary School")),
    School(name="Aukamm Elementary School"),
    School(name="Mason-Rice Elementary")
]
user.save()

我正在使用此代码检索users在其领域拥有特定学校的人schools：

users = User.objects(school__match={"name": "Aukamm Elementary School"})

我只想获得Aukamm Elementary School在学校领域中的选定学校。

接收

[
    {
        "first_name": "Rohit",
        "last_name": "Khatri",
        "schools": [
            {
                "name": "Auden High School"
            },
            {
                "name": "Baldwin Boys High School"
            },
            {
                "name": "Baldwin Girls High School"
            },
            {
                "name": "Aukamm Elementary School"
            },
            {
                "name": "Mason-Rice Elementary"
            }
        ]
    },
    {
        "first_name": "ABC",
        "last_name": "DEF",
        "schools": [
            {
                "name": "Little Harbor Elementary School"
            },
            {
                "name": "Aukamm Elementary School"
            },
            {
                "name": "Mason-Rice Elementary"
            }
        ]
    }
]

所需输出

[
    {
        "first_name": "Rohit",
        "last_name": "Khatri",
        "schools": [
            {
                "name": "Aukamm Elementary School"
            }
        ]
    },
    {
        "first_name": "ABC",
        "last_name": "DEF",
        "schools": [
            {
                "name": "Aukamm Elementary School"
            }
        ]
    }
]

谢谢

4

1 回答 1

2

您可以将函数中的$filter运算符aggregate用作

users = User.objects(school__match={ "name": "Aukamm Elementary School" }).aggregate(
    { "$project": {
        "first_name": 1,
        "last_name": 1,
        "schools": {
             "$filter": {
                  "input": "$schools",
                  "as": "school",
                  "cond": { "$eq": [ "$$school.name", "Aukamm Elementary School" ] }
             }
        }
    } }
)
于 2016-12-23T14:11:24.580 回答