MongoCollection.find() does search twice?

Question

I am using the code snupped as below :

if (collection.find(toFind) != null) {
            dataFound = collection.find(toFind).first();
        } else {
            System.err.println("NULL");
        }

As collection.find() is being called twice here, will that be performing 2 searches on database or becasue it returns a FindIterable, its just a cusror???

We are restricted to limit the database operations and avoid as much necessary, as we are paying it per request unit

Why do you need that null check in the first place? Wouldn't find always return a result, even if it is empty? — Thilo, Jul 01 '19 at 13:30
YES - FindIterableImpl will return a result..even if its empty. I can modify my check like - `if (collection.find(toFind).count() > 0) { dataFound = collection.find(toFind).first(); } else { System.err.println("EMPTY"); }` but still the question remain, whether the .find() will be called twice ?? i would expect it would return a cursor and the cursor will not close until a further operation like first(), sort(), filter(), etc are called Does that clarify my original question? Any documentation around that — Chirag Mehta, Jul 03 '19 at 11:37

score 2 · Answer 1 · answered Jul 01 '19 at 11:30

Why not store the find result and then use the store variable

var queryResult = collection.find(toFind)
if(queryResult != null){
 dataFound = queryResult.first()
} else { // Handle error here}

Or better yet just use the findOne method to get the first result

var queryResult = collection.findOne(toFind)
if(!queryResult){
  //Handle result here
}

And to answer the question, yes it will perform the query twice.

MongoCollection.find() does search twice?

1 Answers1