Tutorial by Examples: l

To normalize the database in the second form, there must not be any partial dependency of any column on primary key. Let's consider the following example: idnamedobsubject1Mark1-1-1981Physics2Jack2-2-1982Math2Jack2-2-1982Biology3John3-3-1983Math This table is considered to have a composite primar...

If a java library contains interfaces that should be implemented by the user (e.g. click listeners like View.IOnClickListener or callbacks), the implementing class has to inherit -- directly or indirectly -- from Java.Lang.Object or Java.Lang.Throwable. This is a common error, because the packaging ...

The REPLACE statement can work with regular expressions directly: DATA(lv_test) = 'The quick brown fox'. REPLACE ALL OCCURRENCES OF REGEX '\wo' IN lv_test WITH 'XX'. The variable lv_test will evaluate to The quick bXXwn XXx.

For more advanced regex operations it's best to use CL_ABAP_REGEX and its related classes. DATA: lv_test TYPE string, lo_regex TYPE REF TO cl_abap_regex. lv_test = 'The quick brown fox'. CREATE OBJECT lo_regex EXPORTING pattern = 'q(...)\w'. DATA(lo_matcher) = lo_regex->cr...

Step 1. In your host machine (Windows/Linux/OSX), create an empty dir my_project. Step 2. Create a file named Vagrantfile with this: Vagrant.configure("2") do |config| config.vm.box = "gbarbieru/xenial" #An Ubuntu 16.04 based image config.vm.hostname = "my_project&...

To preload remote images and ensure that the image is only downloaded once: Glide.with(context) .load(yourUrl) .diskCacheStrategy(DiskCacheStrategy.SOURCE) .preload(); Then: Glide.with(context) .load(yourUrl) .diskCacheStrategy(DiskCacheStrategy.SOURCE) // ALL works her...

The first mistake that nearly every single programmer makes is presuming that this code will work as intended: float total = 0; for(float a = 0; a != 2; a += 0.01f) { total += a; } The novice programmer assumes that this will sum up every single number in the range 0, 0.01, 0.02, 0.03, .....

for numbers, a zero value evaluates to false, non zero to true int i = 0 ... if (i) print "some ${i}" else print "nothing" will print "nothing"

a string (including GStrings) evaluates to true if not null and not empty, false if null or empty def s = '' ... if (s) println 's is not empty' else println 's is empty' will print: 's is empty'

Collections and Maps evaluates to true if not null and not empty and false if null or empty /* an empty map example*/ def userInfo = [:] if (!userInfo) userInfo << ['user': 'Groot', 'species' : 'unknown' ] will add user: 'Groot' , species : 'unknown' as default userInfo since the u...

a null object reference evaluates to false, a non null reference to true, but for for strings, collections, iterators and enumerations it also takes into account the size. def m = null if (!m) println "empty" else println "${m}" will print "empty" de...

Sometimes it may be useful to have a specific asBoolean definition in your own program for some kind of objects. /** an oversimplified robot controller */ class RunController { def complexCondition int position = 0 def asBoolean() { return complexCondition(this...

my @data_array = (123, 456, 789, 'poi', 'uyt', "rew", "qas"); print Dumper @data_array; Using Data::Dumper gives an easy access to fetch list values. The Dumper returns the list values serialized in a way that looks like Perl code. Output: $VAR1 = 123; $VAR2 = 456; $VAR3 ...

HTML template files are always loaded before everything else Files beginning with main. are loaded last Files inside any lib/ directory are loaded next Files with deeper paths are loaded next Files are then loaded in alphabetical order of the entire path Reference Link Reference page: Mete...

You can default to the normal Mongo format by defining your collections with the idGeneration field. MyCollection = new Meteor.Collection('mycollection', {idGeneration : 'MONGO'});

You can get it either synchronously: var docId = Todos.insert({text: 'foo'}); console.log(docId); Or asynchronously: Todos.insert({text: 'foo'}, function(error, docId){ console.log(docId); });

Simple pattern for filtering subscriptions on the server, using regexes, reactive session variables, and deps autoruns. // create our collection WordList = new Meteor.Collection("wordlist"); // and a default session variable to hold the value we're searching for Session.setDefault('...

Geospatial collections generally involve storing GeoJSON in the Mongo database, streaming that data to the client, accessing the browser's window.navigator.geolocation, loading up a Map API, converting GeoJSON to LatLngs, and plotting on the map. Preferably all in realtime. Here are a list of reso...

The following example will log all of your collection queries to the server console in realtime. Meteor.startup( function () { var wrappedFind = Meteor.Collection.prototype.find; // console.log('[startup] wrapping Collection.find') Meteor.Collection.prot...

Texttastic Code Editor - Code editor with syntax highlighting for iOS devices. Working Copy - Clone Github repositories to your iPad and code on the go. CodeHub - Browse and maintain your GitHub repositories. Management tool. iOctocat - Social utility for following Github projects. iMockups fo...