Tutorial by Examples: l

COALESCE ()

COALESCE () Evaluates the arguments in order and returns the current value of the first expression that initially does not evaluate to NULL. DECLARE @MyInt int -- variable is null until it is set with value. DECLARE @MyInt2 int -- variable is null until it is set with value. DECLARE @MyInt3 int -...

Microsoft SQL Server • NULLs

Constructing a DP Solution

No matter how many problems you solve using dynamic programming(DP), it can still surprise you. But as everything else in life, practice makes you better. Keeping these in mind, we'll look at the process of constructing a solution for DP problems. Other examples on this topic will help you understan...

dynamic-programming • Getting started with dynamic-programming

Public Gist

A public gist can be almost anything. A simple example of a Javascript function: function randomInt(min, max) { return Math.floor((max - min + 1) * Math.random()) + min; }

github • Using Gist

Service Class

Controller is an entry point to our application. However, it’s not the only possible entry point. I would like to have my logic accessible from: Rake tasks background jobs console tests If I throw my logic into a controller it won’t be accessible from all these places. So let’s try “skinny ...

Ruby on Rails • Class Organization

UPSERT - INSERT ... ON CONFLICT DO UPDATE...

since version 9.5 postgres offers UPSERT functionality with INSERT statement. Say you have a table called my_table, created in several previous examples. We insert a row, returning PK value of inserted row: b=# INSERT INTO my_table (name,contact_number) values ('one',333) RETURNING id; id ---- ...

postgresql • INSERT

Client side exporting

You need to add a reference of the file called offline-exporting.js to make the client side exporting available. Please be noted this feature is not supported in browser IE 8, So if you load this chart in any unsupported browser, the module will fall back to the export server. This can be handled wi...

highcharts • Exporting

Connect to Server, Create Table, Query Data

Install the package: $ pip install pymssql import pymssql SERVER = "servername" USER = "username" PASSWORD = "password" DATABASE = "dbname" connection = pymssql.connect(server=SERVER, user=USER, password=PASSWORD, database=DATABASE...

Python Language • Connecting Python to SQL Server

Email Clients and Rendering Engines

Email clients use different rendering engines to render HTML emails: Apple Mail, Outlook for Mac, Android Mail and iOS Mail use WebKit Outlook 2000/02/03 use Internet Explorer 6 Outlook 2007/10/13 use Microsoft Word Web clients use their browser’s respective engine (e.g. Safari uses WebKit, Ch...

email • Getting started with email

Read text file with comma delimiter

DATA table-name; INFILE "file-path/file-name.csv" dsd; INPUT Name $ City $ Age; RUN;

sas • Reading Data

InvocationExpression Class

InvocationExpression class allows invocation of other lambda expressions that are parts of the same Expression tree. You create them with static Expression.Invoke method. Problem We want to get on the items which have "car" in their description. We need to check it for null before searc...

.NET Framework • Expression Trees

The Basics (Tables and Inline CSS)

Tables for Layout The structure of an HTML email file is similar to that of a web page: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Hello!</title> </head> <body> &...

email • Getting started with email

Display EdgeHTML mode

The IE=Edge meta tag is for telling the destination rendering engine to use the latest (edge) version of IE rendering engine, which enables responsive behavior in Windows phones. <meta http-equiv="X-UA-Compatible" content="IE=edge"> Occasionally this breaks images in Li...

email • Meta Information

Disable auto-scale in iOS 10 Mail

Apple iOS 10 Mail doesn't always auto-scale non-responsive emails. The auto-scale meta tag can be used to disable auto-scale feature in iOS 10 Mail entirely. <meta name="x-apple-disable-message-reformatting">

email • Meta Information

Using a TestScheduler to advance time manually

Most Rx operators take an optional scheduler on which to schedule their future iterations. If not supplied they will use their default configured scheduler. Supplying a scheduler can be useful for testing purposes in which we like to talk about virtual time instead of real time for speed of test exe...

rxjs • Scheduler

Self Referencing Employee Table

ms-access • Self-Referencing tables

Tuples within Collections

Tuples are often used within collections but they must be handled in a specific way. For example, given the following list of tuples: scala> val l = List(1 -> 2, 2 -> 3, 3 -> 4) l: List[(Int, Int)] = List((1,2), (2,3), (3,4)) It may seem natural to add the elements together using im...

Scala Language • Tuples

TRUNCATE clause

Use this to reset the table to the condition at which it was created. This deletes all rows and resets values such as auto-increment. It also doesn't log each individual row deletion. TRUNCATE TABLE Employees

SQL • DELETE

Interval Scheduling

We have a set of jobs J={a,b,c,d,e,f,g}. Let j in J be a job than its start at sj and ends at fj. Two jobs are compatible if they don't overlap. A picture as example: The goal is to find the maximum subset of mutually compatible jobs. There are several greedy approaches for this problem: Earli...

algorithm • Applications of Greedy technique

Read subset of a global raster defined by a bounding box

Open a raster that covers the globe and extract a subset of the raster. import gdal # Path to a tiff file covering the globe # http://visibleearth.nasa.gov/view.php?id=57752 tif_name = "/path_name/land_shallow_topo_21600.tif" # Open raster in read only mode ds = gdal.Open(tif_n...

gdal • Reading rasters with gdal

Recursive Solution

Matrix chain multiplication is an optimization problem that can be solved using dynamic programming. Given a sequence of matrices, the goal is to find the most efficient way to multiply these matrices. The problem is not actually to perform the multiplications, but merely to decide the sequence of t...

dynamic-programming • Matrix Chain Multiplication