如何在 mongodb-native findOne() 中使用变量作为字段名? [英] How to use a variable as a field name in mongodb-native findOne()?

问题描述

我在 mongodb 中有这些数据:

I have this data in mongodb:

{  
    "name": "Amey",
    "country": "India",
    "region": "Dhule,Maharashtra"
}

并且我想在将字段名称作为查询中的变量传递时检索数据.

and I want to retrieve the data while passing a field name as a variable in query.

以下不起作用:

var name = req.params.name;
var value = req.params.value;
collection.findOne({name: value}, function(err, item) {
    res.send(item);
});

如何查询 mongodb 以保持字段名称及其值动态?

How can I query mongodb keeping both field name and its value dynamic?

推荐答案

需要动态设置查询对象的key:

You need to set the key of the query object dynamically:

var name = req.params.name;
var value = req.params.value;
var query = {};
query[name] = value;
collection.findOne(query, function (err, item) { ... });

当您执行{name: value} 时，键是字符串'name' 而不是变量name 的值.

When you do {name: value}, the key is the string 'name' and not the value of the variable name.

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