Jacke

SQL language proposal: JOIN FOREIGN

The idea is to improve the SQL language, specifically the join syntax, for the special but common case when joining on foreign key columns.

The problem

Example below taken from PostgreSQL documentation [1]

In SQL-89, we didn't have any JOIN syntax yet, so queries were written in this way:

Jacke

JNI Example (Mac OS)

JNI (Java Native Interface) allows implementing methods in C/C++, and use them in Java.

1. Create JNIExample.java file

class JNIExample {

  // Native method, no body.

Jacke

public class HelloJNI {
    static {
        System.loadLibrary("hello");    // loads libhello.so
    }

    private native void sayHello(String name);

    public static void main(String[] args) {
        new HelloJNI().sayHello("Dave");
    }

Jacke

reference

• https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands

cheatsheet

• https://cloud.google.com/anthos/gke/docs/on-prem/reference/cheatsheet
• https://medium.com/flant-com/kubectl-commands-and-tips-7b33de0c5476
• https://prefetch.net/blog/2019/10/16/the-beginners-guide-to-creating-kubernetes-manifests/
• https://kubernetes.io/docs/user-guide/kubectl-cheatsheet/
• https://learnk8s.io/blog/kubectl-productivity/
• https://medium.com/faun/kubectl-commands-cheatsheet-43ce8f13adfb

Jacke

abstract class Animal {
 def name: String
}

abstract class Pet extends Animal {}

class Cat extends Pet {
  override def name: String = "Cat"
}

Jacke

class Graph {
  class Node {
    var connectedNodes: List[Graph#Node] = Nil
    def connectTo(node: Graph#Node): Unit = {
      if (!connectedNodes.exists(node.equals)) {
        connectedNodes = node :: connectedNodes
      }
    }
  }
  var nodes: List[Node] = Nil

Jacke

Shortcut — Action

• CTRL + A — Move to the beginning of the line
• CTRL + E — Move to the end of the line
• CTRL + [left arrow] — Move one word backward (on some systems this is ALT + B)
• CTRL + [right arrow] — Move one word forward (on some systems this is ALT + F)
• CTRL + U — (bash) Clear the characters on the line before the current cursor position
• CTRL + U —(zsh) If you're using the zsh, this will clear the entire line
• CTRL + K — Clear the characters on the line after the current cursor position
• ESC + [backspace] — Delete the word in front of the cursor

Jacke

import io.Source
import scala.util.control.Breaks._

/**
 * Scala TicTacToe game without any side effects
 * 
 * Written in response to following post (which also contains task description):
 *   http://blog.tmorris.net/scala-exercise-with-types-and-abstraction/
 */
object TicTacToe {

Jacke

Code examples knowledge base

• Generated by code-examples-manager release 2.1.2
• 342 published examples

akka

• akka-actors-hello-world.sc : Simple akka hello world example
• akka-http-client-json-stream.sc : Fully asynchronous http client call with json streamed response using akka-http will work in all cases, even with chunked responses !
• akka-http-client-json-with-proxy.sc : Fully asynchronous http client call with json response using akka-http will work in all cases, even with chunked responses, this example add automatic http proxy support.
• akka-http-client-json.sc : Fully asynchronous http client call with json response using akka-http will work in all cases, even with chunked responses !
• [akka-http-client-s

Jacke

/*  Relational (SQL) Database Normalization

Normalization:
- Every non-key attribute must provide a fact about the key, the whole key, and nothing but the key. (3NF)
- Reduction and elimination of redundant data

- Example: A post in a blog, each post will have an author e-mail but if you needed to update the e-mail address of 'Andrew', you should only have to do it once (and not for each post).

Examples of un-normalized databases:
(https://en.wikipedia.org/wiki/Database_normalization)