What is the right way to make a synchronous MongoDB query in Node.js?

Question

I\'m using the Node.JS driver for MongoDB, and I\'d like to perform a synchronous query, like such:

function getAThing()
{
    var db = new mongo.Db(\"mydata         


        

Answer 1

While it's not strictly synchronous, a pattern I've repeatedly adopted and found very useful is to use co and promisify yield on asynchronous functions. For mongo, you could rewrite the above:

var query = co( function* () {

    var db = new mongo.Db("mydatabase", server, {});
    db = promisify.object( db );
    db = yield db.open();

    yield db.authenticate("myuser", "mypassword");

    var collection = yield db.collection("Things");
    return yield collection.findOne( { name : "bob"} );

});

query.then( result => {

} ).catch( err => {

} );

This means:

1. You can write "synchronous"-like code with any asynchronous library
2. Errors are thrown from the callbacks, meaning you don't need the success check
3. You can pass the result as a promise to any other piece of code