Tutorial by Examples: et

A frequent reason why your read operation may not work is because your security rules reject the operation, for example because you're not authenticated (by default a database can only be accessed by an authenticated user). You can see these security rule violations in the logcat output. But it's e...

$collection = Mage::getModel('catalog/product') ->getCollection() ->setPageSize(20) ->setCurPage(1);

Large scale applications often need different properties when running on different environments. we can achieve this by passing arguments to NodeJs application and using same argument in node process to load specific environment property file. Suppose we have two property files for different enviro...

function positive() { return 0 } function negative() { return 1 }

if true; then echo Always executed fi if false; then echo Never executed fi

Installations Download and install: Java 8 - download the relevant installation from Oracle site. Activator - download zip from www.playframework.com/download and extract files to the target Play folder, for example to: c:\Play-2.4.2\activator-dist-1.3.5 sbt - download from www.sc...

This serializer has some nice features that the default .net json serializer doesn't have, like Null value handling, you just need to create the JsonSerializerSettings : public static string Serialize(T obj) { string result = JsonConvert.SerializeObject(obj, new JsonSerializerSettings { NullVa...

You can make a URI parameter optional by adding a question mark to the route parameter. You can also specify a default value by using the form parameter=value. public class BooksController : Controller { // eg: /books // eg: /books/1430210079 [Route(“books/{isbn?}”)] public Act...

Another way of doing aggregations is by using the Mongo.Collection#rawCollection() This can only be run on the Server. Here is an example you can use in Meteor 1.3 and higher: Meteor.methods({ 'aggregateUsers'(someId) { const collection = MyCollection.rawCollection() const aggre...

Logs are very important. Recreate an error context can be sometimes very painful due to the lack of information about how and when the error occurred. This example shows: How to add user's data in the error logs How to add post parameters sent when an error occurred How to use WebPr...

Java Code import org.opencv.core.Mat; import org.opencv.core.MatOfRect; import org.opencv.core.Point; import org.opencv.core.Rect; import org.opencv.core.Scalar; import org.opencv.highgui.Highgui; import org.opencv.highgui.VideoCapture; import org.opencv.objdetect.CascadeClassifier; publ...

Let us assume we have the following two DataFrames: In [7]: df1 Out[7]: A B 0 a1 b1 1 a2 b2 In [8]: df2 Out[8]: B C 0 b1 c1 The two DataFrames are not required to have the same set of columns. The append method does not change either of the original DataFrames. Inst...

Sometimes you need to replace a value matching a pattern with a new value that's based on that specific match, making it impossible to predict the new value. For these types of scenarios, a MatchEvaluator can be very useful. In PowerShell, a MatchEvaluator is as simple as a scriptblock with a singl...

You can delete existing snapshots of database using DELETE DATABASE statement: DROP DATABASE Mydatabase_morning In this statement you should reference name of the database snapshot.

The typeof a tuple is a subtype of Tuple: julia> typeof((1, 2, 3)) Tuple{Int64,Int64,Int64} julia> typeof((1.0, :x, (1, 2))) Tuple{Float64,Symbol,Tuple{Int64,Int64}} Unlike other data types, Tuple types are covariant. Other data types in Julia are generally invariant. Thus, julia>...

Because Julia function parameter lists are themselves tuples, dispatching on various kinds of tuples is often easier done through the method parameters themselves, often with liberal usage for the "splatting" ... operator. For instance, consider the implementation of reverse for tuples, fr...

Tuples are frequently used for multiple return values. Much of the standard library, including two of the functions of the iterable interface (next and done), returns tuples containing two related but distinct values. The parentheses around tuples can be omitted in certain situations, making multip...

RowAB1FruitApple2WeekdayMonday3AnimalDog Formula on C1 ={A1:A3} Result RowC1Fruit2Weekday3Dog Alternative formula =ARRAYFORMULA(A1:A3)

Create an instance of Mobile Analytics for Bluemix. Add the Bluemix Mobile Services SDK to your iOS project. After installing the SDK, add these import statements at top of your AppDelegate.swift file: import BMSCore import BMSAnalytics Next you'll need to initialize and send mobile ana...

Setup Install AWS CLI AWS CLI is an common CLI tool for managing the AWS resources. With this single tool we can manage all the aws resources sudo apt-get install -y python-dev python-pip sudo pip install awscli aws --version aws configure Bash one-liners cat <file> # output a file ...