Tutorial by Examples: co

db.originalName.renameCollection("newName" );

With the power of regex comes great responsibility.... db.posts.find({'text': /.*foo.*|.*bar.*/i})

db.posts.find().forEach(function(doc){ if(doc.commentsBlobId){ var commentsBlob = db.comments.findOne({'_id': commentsBlobId }); db.posts.update({_id: doc._id}, {$set:{'comments': commentsBlob }}, false, true); } });

db.posts.find().forEach(function(doc){ if(doc.foo === 'bar'){ db.posts.remove({_id: doc._id}); } });

db.posts.find().forEach(function(doc){ db.accounts.update({_id: doc._id}, {$set: {'_id': doc._id.str }}, false, true); });

var newvalue = ""; db.posts.find().forEach(function(doc){ if(doc.foo){ newvalue = '"' + doc.foo + '"'; db.accounts.update({_id: doc._id}, {$set: {'doc.foo': newvalue}}); } });

var newvalue = null; db.posts.find().forEach(function(doc){ if(doc.foo){ newvalue = '"' + doc.foo + '"'; db.accounts.update({_id: doc._id}, {$set: {'doc.foo': newvalue}}); } });

What we're doing here is referencing the array index using dot notation db.posts.find({"tags.0": {$exists: true }})

This project is a self-contained example done completely in the Interface Builder. You should be able to work through it in 10 minutes or less. Then you can apply the concepts you learned to your own project. Here I just use UIViews but they can represent whatever view you like (ie, button, label...

If you are just starting a new project, it's important to think about how you want to handle code signing. If you are new to code signing, check out the WWDC session that describes the fundamentals of code signing in Xcode. To properly code-sign your app, you have to have the following resources o...

This example illustrates how to configure Jersey so that you can begin using it as a JAX-RS implementation framework for your RESTful API. Assuming that you have already installed Apache Maven, follow these steps to set up Jersey: Create maven web project structure, in terminal (windows) execute...

For programs with a single source file, using gcc is simple. /* File name is hello_world.c */ #include <stdio.h> int main(void) { int i; printf("Hello world!\n"); } To compile the file hello_world.c from the command line: gcc hello_world.c gcc will then compil...

Dependency Injection (DI) in the context of using a Dependency Injection Container (DIC) can be seen as a superset of constructor injection. A DIC will typically analyze a class constructor's typehints and resolve its needs, effectively injecting the dependencies needed for the instance execution. ...

A constructor is a special method in a class that is called when an instance of an object is created. It is a regular MATLAB function that accepts input parameters but it also must follow certain rules. Constructors are not required as MATLAB creates a default one. In practice, however, this is a p...

Create a new project It can be just a Single View Application. Add the code Create a new Cocoa Touch Class file (File > New > File... > iOS > Cocoa Touch Class). Name it MyCollectionViewCell. This class will hold the outlets for the views that you add to your cell in the storyboard. ...

The following might have undefined behavior due to incorrect pointer alignment: char *memory_block = calloc(sizeof(uint32_t) + 1, 1); uint32_t *intptr = (uint32_t*)(memory_block + 1); /* possible undefined behavior */ uint32_t mvalue = *intptr; The undefined behavior happens as the pointer...

While there are many different control sequences for io:format and io_lib:format, most of the time you'll use only three different ones: ~s, ~p and ~w. ~s The ~s is for strings. It prints strings, binaries and atoms. (Anything else will cause a badarg error.) It doesn't quote or escape anything...

If you are inside a folder of a git repository it might be nice to show the current branch you are on. In ~/.bashrc or /etc/bashrc add the following (git is required for this to work): function prompt_command { # Check if we are inside a git repository if git status > /dev/null 2>&a...

There are many cases when one has created an NSDate from only an hour and minute format, i.e: 08:12 The downside for this situation is that your NSDate is almost completely "naked" and what you need to do is to create: day, month, year, second and time zone in order to this object to &quo...

If ww have NSDate object, and we want to convert it into NSString. There are different types of Date strings. How we can do that?, It is very simple. Just 3 steps. Create NSDateFormatter Object NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; Set the date format in whi...