MongoDB查询嵌套数组

时间:2018-02-07 12:16:29

标签: arrays mongodb meteor mongo-shell minimongo

我在查询Mongo Collection时遇到了一些麻烦。

我有一个像这样的集合:

{
"_id" : "555bd34329de3cf232434ef2",
"cars" : [ 
    {
        "0" : {
            "parts" : [ 
                {
                    "name" : "x1",
                    "price" : 12
                },
                {
                    "name" : "x2",
                    "price" : 14
                }
            ]
        },
        "1" : {
            "parts" : [ 
                {
                    "name" : "y1",
                    "price" : 8
                },
                {
                    "name" : "y2",
                    "price" : 12
                }
            ]
        } 
    }
]
}

我想回复以下内容:

"parts" : [ 
    {
        "name" : "x1",
        "price" : 12
    },
    {
        "name" : "x2",
        "price" : 14
    }
]

换句话说,我需要弄清楚如何通过两个参数同时查询Collection:

  • ID匹配" 555bd34329de3cf232434ef2"

  • 其中" name"部分匹配" x1"

有谁知道如何进行这种嵌套查询?

1 个答案:

答案 0 :(得分:0)

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的位置:

{
    "cars" : [ 
        {
            "parts" : [ 
                {
                    "name" : "x1",
                    "price" : 12
                }, 
                {
                    "name" : "x2",
                    "price" : 14
                }
            ]
        }
    ]
}

如果这不够好,你可以更接近使用聚合框架......