如何在mongo集合

Question

我有两个名为ServiceProvider和Parents的集合。

的ServiceProvider：

{
    "_id" : ObjectId("57235dc9588aec3e318b4567"),
    "ServiceProviderID" : 3,
    "Title" : "test",
    "PostedMessage" : "test",
    "TotalComments" : 0,
    "TotalShares" : 0,
    "TotalThanks" : 0,
    "AddedOn" : "2016-04-29",
    "LastModifiedOn" : "2016-04-29",
    "PostAttachment" : {
        "ImagePath" : ""
    },
    "PostComments" : [
        {
            "_id" : "14619355772980176",
            "UserID" : 3,
            "CommentMessage" : "test",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-29",
            "LastModifiedOn" : "2016-04-29",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        },
        {
            "_id" : "1461935582156657330",
            "UserID" : 3,
            "CommentMessage" : "123",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-29",
            "LastModifiedOn" : "2016-04-29",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        },
        {
            "_id" : "14619892452027996767",
            "UserID" : 3,
            "CommentMessage" : "45",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-30",
            "LastModifiedOn" : "2016-04-30",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        },
        {
            "_id" : "14619896331049580283",
            "UserID" : 3,
            "CommentMessage" : "46",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-30",
            "LastModifiedOn" : "2016-04-30",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        }
    ],
    "Subscriber" : [ ]
}

父母：

{
"35" : {
        "ID" : "133",
        "UID" : "7Cv1y3kjutSWgvhtH1Lp9yEDOeiFR0aAbB77uTnEJCR3HSH0s6eC7rEt",
        "Name" : "Ash Nan",
        "ProfileImagePath" : null
    },
    "36" : {
        "ID" : "134",
        "UID" : "2BRcj3xBnNzse7YiudouwmYprilzjkbrC4Yk7v9gPBcs6eC7rEt",
        "Name" : "Test 45",
        "ProfileImagePath" : "Chrysanthemum_134_1450777239#SIZE#.jpg"
    },
    "37" : {
        "ID" : "135",
        "UID" : "BCMMdFjfO7WXzESWQ8Wlnge4gMQoumBxXyY99NIou5UzKrRgs6eC7rEt",
        "Name" : "test 45",
        "ProfileImagePath" : "Penguins_135_1450777743#SIZE#.jpg"
    },
    "38" : {
        "ID" : "136",
        "UID" : "HxFmh7T4balaAbB77UTEgJtrxXyY99zCUEYeaAbB77SF11rKv8ad9FS6Tss6eC7rEt",
        "Name" : "test1 test1",
        "ProfileImagePath" : null
    },
}

如何使用Parents集合对Postcomments子文档执行查询查询？

我想将来自Parents集合的Name字段插入ServiceProvider Postcomments子文档中。

我希望查询返回以下内容：

{
    "_id" : ObjectId("57235dc9588aec3e318b4567"),
    "ServiceProviderID" : 3,
    "Title" : "test",
    "PostedMessage" : "test",
    "TotalComments" : 0,
    "TotalShares" : 0,
    "TotalThanks" : 0,
    "AddedOn" : "2016-04-29",
    "LastModifiedOn" : "2016-04-29",
    "PostAttachment" : {
        "ImagePath" : ""
    },
    "PostComments" : [
        {
            "_id" : "14619355772980176",
            "UserID" : 3,
            "UserName" : "Chinmay Kulkarni",
            "CommentMessage" : "test",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-29",
            "LastModifiedOn" : "2016-04-29",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        },
        {
            "_id" : "1461935582156657330",
            "UserID" : 3,
            "UserName" : "Chinmay Kulkarni",
            "CommentMessage" : "123",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-29",
            "LastModifiedOn" : "2016-04-29",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        },
        {
            "_id" : "14619892452027996767",
            "UserID" : 3,
            "UserName" : "Chinmay Kulkarni",
            "CommentMessage" : "45",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-30",
            "LastModifiedOn" : "2016-04-30",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        },
        {
            "_id" : "14619896331049580283",
            "UserID" : 3,
            "UserName" : "Chinmay Kulkarni",
            "CommentMessage" : "46",
            "TotalThanks" : 0,
            "AddedOn" : "2016-04-30",
            "LastModifiedOn" : "2016-04-30",
            "CommentAttachment" : {
                "ImagePath" : ""
            }
        }
    ],
    "Subscriber" : [ ]
}

我指的是this链接，但没有通过。任何帮助，将不胜感激。谢谢！