在mongodb中获取嵌套的条件数组文档

Question

collection : { 
    "_id" : ObjectId("5ab7757d3295a10bac3ad927"), 
    "resource_id" : "msh", 
    "resource_name" : "m", 
    "projects" : [
        {
            "project_id" : "ABC", 
            "project_name" : "test1", 
            "allocation" : [
                {
                    "month_fte" : 0.4, 
                    "month" : ISODate("2018-01-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.2, 
                    "month" : ISODate("2018-02-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.9, 
                    "month" : ISODate("2018-03-01T00:00:00.000+0000")
                }
            ]
        }, 
        {
            "project_id" : "XYZ", 
            "project_name" : "test2", 
            "allocation" : [
                {
                    "month_fte" : 0.1, 
                    "month" : ISODate("2018-01-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.5, 
                    "month" : ISODate("2018-02-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.4, 
                    "month" : ISODate("2018-03-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.4, 
                    "month" : ISODate("2018-04-01T00:00:00.000+0000")
                }
            ]
        }
    ] } { 
    "_id" : ObjectId("5ab7757d3295a10bac3ad928"), 
    "resource_id" : "rp", 
    "resource_name" : "r", 
    "projects" : [
        {
            "project_id" : "8P0CHF", 
            "project_name" : "test1", 
            "allocation" : [
                {
                    "month_fte" : 1.0, 
                    "month" : ISODate("2018-01-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.5, 
                    "month" : ISODate("2018-02-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.3, 
                    "month" : ISODate("2018-03-01T00:00:00.000+0000")
                }
            ]
        }, 
        {
            "project_id" : "8P0ABC", 
            "project_name" : "test3", 
            "allocation" : [
                {
                    "month_fte" : 0.1, 
                    "month" : ISODate("2018-04-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.5, 
                    "month" : ISODate("2018-05-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.4, 
                    "month" : ISODate("2018-06-01T00:00:00.000+0000")
                }
            ]
        }
    ] }

查询：

db.resource.find({

    $and: [
        { 'projects.allocation.month' : { $gt: ISODate("2018-01-01T00:00:00.000+0000") } }, 
        { 'projects.allocation.month': { $lt: ISODate("2018-03-01T00:00:00.000+0000") } }
    ]
    })

输出：

{ 
    "_id" : ObjectId("5ab7757d3295a10bac3ad927"), 
    "resource_id" : "mshirgir", 
    "resource_name" : "manoj shirgire", 
    "projects" : [
        {
            "project_id" : "8P0CHF", 
            "project_name" : "test1", 
            "allocation" : [
                {
                    "month_fte" : 0.4, 
                    "month" : ISODate("2018-01-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.2, 
                    "month" : ISODate("2018-02-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.9, 
                    "month" : ISODate("2018-03-01T00:00:00.000+0000")
                }
            ]
        }, 
        {
            "project_id" : "8P0XYZ", 
            "project_name" : "test2", 
            "allocation" : [
                {
                    "month_fte" : 0.1, 
                    "month" : ISODate("2018-01-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.5, 
                    "month" : ISODate("2018-02-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.4, 
                    "month" : ISODate("2018-03-01T00:00:00.000+0000")
                }, 
                {
                    "month_fte" : 0.4, 
                    "month" : ISODate("2018-04-01T00:00:00.000+0000")
                }
            ]
        }
    ] }

但获得所有分配，如何获得日期条件的分配

Answer 1

您收到的结果是因为如果allocation中的任何一个与您的查询匹配，mongodb会返回整个文档。

如果您想获得 ONLY 匹配的分配，您必须首先解开分配数组。

db.resource.aggregate([
{

    { 
            $unwind:  "$projects.allocation"

    },

},
{

    $match: {

    $and: [
        { 'projects.allocation.month' : { $gt: ISODate("2018-01-01T00:00:00.000+0000") } }, 
        { 'projects.allocation.month': { $lt: ISODate("2018-03-01T00:00:00.000+0000") } }
        ]

    }

}

])