How to use a variable as a field name in mongodb-native findOne()?
Just put the variable in []
var name=req.params.name;
var value = req.params.value;
collection.findOne({[name]:value}, function(err, item) {
res.send(item);
});
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
.
I'd like to clarify that if you're trying to make a query concerning a nested field only (not its value), like if you want to query the field "name" from this document:
{
loc: [0, 3],
unit: {
name : "playername"
}
}
this will work (as in my case - using update):
mdb.cords.updateOne(
{_id: ObjectID(someid)},
{$set: {[query]: newValue}},
function (err, result) {
...
}
}
Simply enclosing [query]
in brackets tells mongodb that it's not literal, but rather a path.