How can I dynamically choose a database named in a string variable?

Question

I want to dynamically call different database collections in my app based on a string like below:

const collection = 'books';
db.${collection}.find()  // turns into db.books.find()

I am using ES6, so if there are any easy ways to do this that would be great! I've been unable to find the way to create this.

EDIT: I am not trying to access part of a object, but anywhere. I'd also want to do something like

${collection}.db.find()

Dynamically accessing variables is usually bad design. Create `name => database` map instead. — Felix Kling, Jun 27 '17 at 22:00
What do you mean by that? In my current case, I am trying to access database names that I may not know in advance. — Ruben Pierre-Antoine, Jun 27 '17 at 22:08
*"I may not know in advance"* In that case how can a variable with that name exist? I'm talking about the `${collection}.db.find()` part. — Felix Kling, Jun 27 '17 at 22:09

score 1 · Answer 1 · answered Jun 27 '17 at 21:10

1

Every property on a JavaScript object can be accessed using square brackets. Like this:

const collection = 'books';
db[collection].find()

answered Jun 27 '17 at 21:10

arjabbar

I am trying to do this anywhere on an object, not just within the properties – Ruben Pierre-Antoine Jun 27 '17 at 21:39

score 0 · Answer 2 · answered Jun 27 '17 at 21:10

0

In case of dynamic strings you should use the format

db[collection].find() // turns into db['books'].find()

object.property
object['property']

are same.

answered Jun 27 '17 at 21:10

Suresh Atta

2 Answers2