通过MongoDB在JSON中查询映射(<字符串，对象>)

Question

如何查询类型为map<字符串，列表>以JSON形式，在MongoDB中？

示例JSON:

{
"WIDTH": 810,
"HEIGHT": 465,
"MODULES": {
"23": {
"XNAME": "COMP1",
"PARAMS": {
"_Klockers": {
"TYPE": "text",
"VALUE": "Klocker#3"
},
"SUBSYS": {
"TYPE": "text",
"VALUE": "2"
},
"EP": {
"TYPE": "integer",
"VALUE": "2"
}
}
},
"24": {
"XNAME": "COMP2",
"PARAMS": {
"_Rockers": {
"TYPE": "text",
"VALUE": "Rocker#3"
},
"Driver": {
"TYPE": "binary",
"VALUE": 1
},
"EP": {
"TYPE": "long",
"VALUE": "233"
}
}
},
"25": {
"XNAME": "COMP3",
"PARAMS": {
"_Mockers": {
"TYPE": "text",
"VALUE": "Mocker#3"
},
"SYSMain": {
"TYPE": "text",
"VALUE": "2342"
},
"TLP": {
"TYPE": "double",
"VALUE": "2.3"
}
}
}
}
}

基本上我想：

1. 列出所有"；XNAME"；"中所有键的字段值；模块"；。预期输出：{"COMP1"、"COMP2"、"COMP3"}
2. 列出所有"；TYPE"；在"；PARAMS"；"的每个键内的对象；模块"；。预期输出：{"文本"、"文本"，"整数"、"文字"、"二进制"、"长"、"正文"、"双"}

我是MongoDB的新手，任何帮助或重定向都将不胜感激。

Answer 1

您可以使用此

db.collection.aggregate([
{
$project: {//You require this as your data is dynamic
"modules": {
"$objectToArray": "$MODULES"
}
}
},
{//Destruct the array
"$unwind": "$modules"
},
{
"$project": {//Again, requires the same as keys are dynamic
"types": {
"$objectToArray": "$modules.v.PARAMS"
},
xname: "$modules.v.XNAME"
}
},
{//Destruct the types
$unwind: "$types"
},
{//Get the distinct values
$group: {
"_id": null,
"xname": {
"$addToSet": "$xname"
},
"types": {
"$addToSet": "$types.v.TYPE"
},

}
}
])