Search for dynamic variable using eval in mongodb

Question

Heyo, I'd like to know if there's a way I can search for a dynamic variable in a mongodb findOne. Ex something that would work like:

var find = 'userID'
var id = '<some id>'

db.collection.findOne({
  eval(find): eval(id)
}, (err, data) => {

  if(err) {
  console.log(err); return;
  }
  
  if(data) {
    //Do stuff
  }
});

Answer 1

findOne expects a normal JSON, try this notation:

findOne({[find]: id})

Following notations are all equivalent:

field = "a";
val = 1;

printjsononeline({ a: 1 });    
printjsononeline({ a: val });    
printjsononeline({ [field]: 1});
printjsononeline({ [field]: val });