MongoDB 查询嵌套数组
MongoDB Querying Nested Arrays
我在查询 Mongo Collection 时遇到了一些问题。
我有一个 Collection 这样的:
{
"_id" : "555bd34329de3cf232434ef2",
"cars" : [
{
"0" : {
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
},
"1" : {
"parts" : [
{
"name" : "y1",
"price" : 8
},
{
"name" : "y2",
"price" : 12
}
]
}
}
]
}
我想return以下内容:
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
换句话说,我需要弄清楚如何同时通过两个参数查询Collection:
其中 ID 匹配“555bd34329de3cf232434ef2”
部分的 "name" 匹配 "x1"
有谁知道如何进行这种嵌套查询吗?
假设文档结构如下:
{
"_id" : ObjectId("555bd34329de3cf232434ef2"),
"cars" : [
{
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
},
{
"parts" : [
{
"name" : "y1",
"price" : 8
},
{
"name" : "y2",
"price" : 12
}
]
}
]
}
您可以运行以下查询:
db.collection.find({ "_id": ObjectId("555bd34329de3cf232434ef2"), "cars.parts.name" : "x1" }, { "_id": 0, "cars.$": 1 })
这将使您非常接近您想要去的地方:
{
"cars" : [
{
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
}
]
}
如果这还不够好,您可以使用聚合框架来更接近...
我在查询 Mongo Collection 时遇到了一些问题。
我有一个 Collection 这样的:
{
"_id" : "555bd34329de3cf232434ef2",
"cars" : [
{
"0" : {
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
},
"1" : {
"parts" : [
{
"name" : "y1",
"price" : 8
},
{
"name" : "y2",
"price" : 12
}
]
}
}
]
}
我想return以下内容:
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
换句话说,我需要弄清楚如何同时通过两个参数查询Collection:
其中 ID 匹配“555bd34329de3cf232434ef2”
部分的 "name" 匹配 "x1"
有谁知道如何进行这种嵌套查询吗?
假设文档结构如下:
{
"_id" : ObjectId("555bd34329de3cf232434ef2"),
"cars" : [
{
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
},
{
"parts" : [
{
"name" : "y1",
"price" : 8
},
{
"name" : "y2",
"price" : 12
}
]
}
]
}
您可以运行以下查询:
db.collection.find({ "_id": ObjectId("555bd34329de3cf232434ef2"), "cars.parts.name" : "x1" }, { "_id": 0, "cars.$": 1 })
这将使您非常接近您想要去的地方:
{
"cars" : [
{
"parts" : [
{
"name" : "x1",
"price" : 12
},
{
"name" : "x2",
"price" : 14
}
]
}
]
}
如果这还不够好,您可以使用聚合框架来更接近...