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mongodb group values by multiple fields
...ems to $push to an array.
db.books.aggregate([
{ "$group": {
"_id": {
"addr": "$addr",
"book": "$book"
},
"bookCount": { "$sum": 1 }
}},
{ "$group": {
"_id": "$_id.addr",
"books": {
"$push": {
"...
Is it bad practice to have a constructor function return a Promise?
...should go in a method of your class. You want to mutate global state? Then call that procedure explicitly, not as a side effect of generating an object. This call can go right after the instantiation:
var engine = new Engine()
engine.displayPosts();
If that task is asynchronous, you can now easil...
How to select html nodes by ID with jquery when the id contains a dot?
...
@Tomalak in comments:
since ID selectors must be preceded by a hash #, there should be no ambiguity here
“#id.class” is a valid selector that requires both an id and a separate class to match; it's valid and not always totally redundant.
The corr...
convert pfx format to p12
...successor to Microsoft's "PFX". PKCS #12 is one of the family of standards called Public-Key Cryptography Standards (PKCS) published by RSA Laboratories.
– AKS
Dec 10 '14 at 10:24
...
nodejs get file name from absolute path?
...
So Nodejs comes with the default global variable called '__fileName' that holds the current file being executed
My advice is to pass the __fileName to a service from any file , so that the retrieval of the fileName is made dynamic
Below, I make use of the fileName string ...
How to sort strings in JavaScript
...m implementations out there, trying to do string comparison more precisely called "natural string sort order"
When "playing" with these implementations, I always noticed some strange "natural sorting order" choice, or rather mistakes (or omissions in the best cases).
Typically, special characters ...
Where is the documentation for the values() method of Enum?
... places :
Enum Types, from The Java Tutorials
The compiler automatically adds some special methods when it creates
an enum. For example, they have a static values method that returns an
array containing all of the values of the enum in the order they are
declared. This method is common...
How to pass macro definition from “make” command line arguments (-D) to C source code?
...
Call make command this way:
make CFLAGS=-Dvar=42
And be sure to use $(CFLAGS) in your compile command in the Makefile. As @jørgensen mentioned , putting the variable assignment after the make command will override the CFL...
Fastest way to convert Image to Byte array
...use an object that has implemented IDisposable, then you should be sure to call Dispose() when you're done with it so that it'll clean up any resources that it has tied up. The using(){} statement just calls it for you when the object goes out of scope of that statement. So you can do myObject.Dispo...
What is the difference between save and insert in Mongo DB?
...s essentially the same.
save behaves differently if it is passed with an "_id" parameter.
For save, If the document contains _id, it will upsert querying the collection on the _id field, If not, it will insert.
If a document does not exist with the specified _id value, the save() method performs an...