mongodb-native findOne()中如何使用变量作为字段名? [英] How to use a variable as a field name in mongodb-native findOne()?
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问题描述
{
name:Amey,
国家:印度,
地区:Dhule,Maharashtra
}
,我想检索一个作为变量传递的字段名称的数据查询。
以下内容不起作用:
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保留字段名称及其值是否动态?
解决方案
您需要动态设置查询对象的密钥:
var name = req.params.name;
var value = req.params.value;
var query = {};
查询[name] = value;
collection.findOne(query,function(err,item){...});
当您执行 {name:value}
,关键是字符串'name'
而不是变量名称
的值。
I have this data in mongodb:
{
"name": "Amey",
"country": "India",
"region": "Dhule,Maharashtra"
}
and I want to retrieve the data querying on a field name passed as a variable.
Following does not work:
var name = req.params.name;
var value = req.params.value;
collection.findOne({name: value}, function(err, item) {
res.send(item);
});
How can I query mongodb keeping both field name and its value dynamic?
解决方案
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) { ... });
When you do {name: value}
, the key is the string 'name'
and not the value of the variable name
.
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