I want to increase a field inside an object object inside a mongodb document by 1.
var stuffID = 5
collection.update({
"id": id,
},
{
'$inc': {
'stuff.stuffID': 1
}
},
function(err, doc) {
res.end('done');
});
I need to make that stuffID a variable. Any way to do that? Thanks.
This is using node-mongodb-native if that helps.
If you're voting to close can you explain what it is you don't understand?
You need to create your variably-keyed object separately, because JS before ES2015 doesn't permit anything other than constant strings in object literal syntax:
var stuffID = 5
var stuff = {}; // create an empty object
stuff['stuff.' + stuffID] = 1; // and then populate the variable key
collection.update({
"id": id,
}, {
"$inc": stuff // pass the object from above here
}, ...);
EDIT in ES2015, it's now possible to use an expression as a key in an object literal, using [expr]: value syntax, and in this case also using ES2015 backtick string interpolation:
var stuffID = 5;
collection.update({
"id": id,
}, {
"$inc": {
[`stuff.${stuffID}`]: 1
}
}, ...);
The code above works in Node.js v4+
Put the variable where it says stuffID.
'stuff.' + varname: 1
