Tutorial by Examples: g

While attached to a running container with a pty assigned (docker run -it ...), you can press ControlP - ControlQ to detach.

Docker is just a fancy way to run a process, not a virtual machine. Therefore, debugging a process "in a container" is also possible "on the host" by simply examining the running container process as a user with the appropriate permissions to inspect those processes on the host (...

Mobile platforms like iOS automatically recognize phone numbers and turn them into tel: links. While the feature is very practical, the system sometimes detects ISBN codes and other numbers as telephone numbers. For mobile Safari and some other WebKit-based mobile browsers to turn off automatic pho...

Orders Table CustomerIdProductIdQuantityPrice12510013220014150021450356700 When grouping by a specific column, only unique values of this column are returned. SELECT customerId FROM orders GROUP BY customerId; Return value: customerId123 Aggregate functions like count() apply to each group...

LOOP has its own IF statement that can control how the clauses are executed: (loop repeat 1000 for x = (random 100) if (evenp x) collect x into evens else collect x into odds finally (return (values evens odds))) Combining multiple clauses in an IF ...

Although it is very tempting to use BETWEEN ... AND ... for a date range, it is problematical. Instead, this pattern avoids most problems: WHERE x >= '2016-02-25' AND x < '2016-02-25' + INTERVAL 5 DAY Advantages: BETWEEN is 'inclusive' thereby including the final date or second. 2...

Using a Recursive CTE, you can generate an inclusive range of dates: Declare @FromDate Date = '2014-04-21', @ToDate Date = '2014-05-02' ;With DateCte (Date) As ( Select @FromDate Union All Select DateAdd(Day, 1, Date) From DateCte Where Date < @T...

Another way you can generate a range of dates is by utilizing a Tally Table to create the dates between the range: Declare @FromDate Date = '2014-04-21', @ToDate Date = '2014-05-02' ;With E1(N) As (Select 1 From (Values (1), (1), (1), (1), (1), (1), (1), (1), (1), (1)) DT...

We can get a comma delimited string from multiple rows using coalesce as shown below. Since table variable is used, we need to execute whole query once. So to make easy to understand, I have added BEGIN and END block. BEGIN --Table variable declaration to store sample records DECLARE @...

Here we demonstrate how to process lists recursively using OCaml's pattern matching syntax. let rec map f lst = match lst with | [] -> [] | hd::tl -> (f hd)::(map f tl) In this case, the pattern [] matches the empty list, while hd::tl matches any list that has at least one element...

Employees table : | ID | FirstName | LastName | Gender | Salary | +------+-----------+----------+--------+--------+ | 1 | Jahangir | Alam | Male | 70000 | | 2 | Arifur | Rahman | Male | 60000 | | 3 | Oli | Ahammed | Male | 45000 | | 4 | Sima | Sulta...

Employees table : | ID | FirstName | LastName | Gender | Salary | +------+-----------+----------+--------+--------+ | 1 | Mark | Hastings | Male | 60000 | | 1 | Mark | Hastings | Male | 60000 | | 2 | Mary | Lambeth | Female | 30000 | | 2 | Mary | Lambe...

Open a text editor (like Notepad), and type the code below: Imports System.ComponentModel Imports System.Drawing Imports System.Windows.Forms Namespace SampleApp Public Class MainForm : Inherits Form Private btnHello As Button ' The form's constructor: thi...

library(caret) # for dummyVars library(RCurl) # download https data library(Metrics) # calculate errors library(xgboost) # model ############################################################################### # Load data from UCI Machine Learning Repository (http://archive.ics.uci.edu/ml/data...

You can use the microbenchmark package to conduct "sub-millisecond accurate timing of expression evaluation". In this example we are comparing the speeds of six equivalent data.table expressions for updating elements in a group, based on a certain condition. More specifically: A data....

================== TODO: Link each of the drawing commands below to their individual examples. I don't know how to do this since the links to the individual examples point towards the "draft" folder. TODO: Add examples for these path "action" commands: stroke(), fill(), clip() ...

context.beginPath() Begins assembling a new set of path commands and also discards any previously assembled path. It also moves the drawing "pen" to the top-left origin of the canvas (==coordinate[0,0]). Although optional, you should ALWAYS start a path with beginPath The discarding ...

import scala.concurrent.Future import scala.concurrent.ExecutionContext.Implicits.global object FutureDivider { def divide(a: Int, b: Int): Future[Int] = Future { // Note that this is integer division. a / b } } Quite simply, the divide method creates a Future tha...

The easiest way to consume a successful Future-- or rather, get the value inside the Future-- is to use the map method. Suppose some code calls the divide method of the FutureDivider object from the "Creating a Future" example. What would the code need to look like to get the quotient of...

Sometimes the computation in a Future can create an exception, which will cause the Future to fail. In the "Creating a Future" example, what if the calling code passed 55 and 0 to the divide method? It'd throw an ArithmeticException after trying to divide by zero, of course. How would t...