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How to properly reuse connection to Mongodb across NodeJs application and modules
...lhost:27017";
var _db;
module.exports = {
connectToServer: function( callback ) {
MongoClient.connect( url, { useNewUrlParser: true }, function( err, client ) {
_db = client.db('test_db');
return callback( err );
} );
},
getDb: function() {
return _db;
}
};
To...
Get names of all keys in the collection
I'd like to get the names of all the keys in a MongoDB collection.
21 Answers
21
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What techniques can be used to speed up C++ compilation times?
...ity that takes advantage of caching techniques to speed things up.
Use Parallelism
Many compilers / IDEs support using multiple cores/CPUs to do compilation simultaneously. In GNU Make (usually used with GCC), use the -j [N] option. In Visual Studio, there's an option under preferences to allow it...
How to use Single TextWatcher for multiple EditTexts?
...idgets in my view layout. Is there a way to use a single TextWatcher for all three EditTexts ?
13 Answers
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How to print a percentage value in python?
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Is float(1) really more pythonic than 1.?
– Tobias Kienzler
Jul 17 '13 at 7:58
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Unique BooleanField value in Django?
... save method of the model and if you've set the boolean to True, make sure all others are set to False.
from django.db import transaction
class Character(models.Model):
name = models.CharField(max_length=255)
is_the_chosen_one = models.BooleanField()
def save(self, *args, **kwargs):
...
What is the purpose of the word 'self'?
...way that makes the instance to which the method belongs be passed automatically, but not received automatically: the first parameter of methods is the instance the method is called on. That makes methods entirely the same as functions, and leaves the actual name to use up to you (although self is th...
Handling an empty UITableView. Print a friendly message
... change the height of your cell to accommodate the empty message. This is all doable but it seems like band-aid on top of band-aid.
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C# Sortable collection which allows duplicate keys
... Use this Comparer e.g. with SortedLists or SortedDictionaries, that don't allow duplicate keys
/// </summary>
/// <typeparam name="TKey"></typeparam>
public class DuplicateKeyComparer<TKey>
:
IComparer<TKey> where TKey : IComparable
{
#...
C#: Assign same value to multiple variables in single statement
...nteresting to know that the get accessor of the intermediate value is not called. Only the set accessor is invoked for all property accessed in the assignation sequence.
Take for example a class that write to the console everytime the get and set accessor are invoked.
static void Main(string[] arg...