Question

我正在尝试根据URL发送的输入查询参数数组从mongodb集合中查询文档。

样本数据库数据

[
    {
        "drawings": {
            "circle": [],
            "square": [
                {
                    "id": "828",
                    "name": "square"
                }
            ],
            "cube": []
    },
    {
        "drawings": {
            "circle": [
                {
                    "id": "827",
                    "name": "circle"
                }
            ],
            "square": [],
            "cube": []
    },
    {
        "drawings": {
            "circle": [],
            "square": [],
            "cube": [
                {
                    "id": "829",
                    "name": "cube"
                }
            ]
    }
]

输入查询参数：

query = ["square","cube"];

预期输出：

[
    {
        "drawings": {
            "circle": [],
            "square": [
                {
                    "id": "828",
                    "name": "square"
                }
            ],
            "cube": []
    },
    {
        "drawings": {
            "circle": [],
            "square": [],
            "cube": [
                {
                    "id": "829",
                    "name": "cube"
                }
            ]
    }
]

最合适的猫鼬查询：

Schema.find({
    $or:[
        {'drawings.square':{$elemMatch:{ name:'square'}}},
        {'drawings.cube':{$elemMatch:{ name:'cube'}}}
    ]
});

尝试以下方法。但是，这是不正确的。

let draw = ["square","cube"];
let draw_query =[];
for (let a=0; a<draw.length;a++){
    draw_query.push("{\"drawings."+ draw[a] +"\':{$elemMatch:{ name:\"" + draw[a] + "\"}}}");
}

它使用单引号字符串创建数组。无法使用。

[ '{"drawings.square":{$elemMatch:{ name:"square"}}}',
  '{"drawings.cube":{$elemMatch:{ name:"cube"}}}' ]

如何动态生成此猫鼬查询？还是有更好的猫鼬查询来达到预期的结果。

Answer 1

您可以直接使用点符号查询它，因此查询应如下所示：

db.collection.find({
  $or: [
    {
      "drawings.square.name": "square"
    },
    {
      "drawings.circle.name": "circle"
    }
  ]
})

您可以使用.map()在JS中进行构建，请尝试：

var query = ["square","cube"];
var orQuery = { $or: query.map(x => ({ [x + ".name"]: x }) ) }

在猫鼬中，基于数组的查询字段

1 个答案: