Operating System
Makes a bit of hardware:
Motherboard
Processor
RAM
Network Card
MAkes the hardware work
Common operating systems were originally written in C
UNIX was the original Paid, closed source
IOS/OSX UNIX derivitive, closed source
Windows Closed
Linux (UNIX-like OS) Open source == good stuff!!
Windows .NET is now open source.
FLOP Floating Point Operation
Programming LAnguage
C > C++(still in use today)
c++ for 'raw coding'
However
Java
runs in JVM (virtual machine)
C#
Microsoft pushing for this
F# > Functional Programming Language
Python
Good for engineering and data science
Give the benfits of C++ without the drawbacks
Cloud
Traditional Computing
Run on local hardware
Today > different
Newer companies are moving services to the cloud
a) AWS Amazon 70%ish of market
b) Azure 25%ish Microsoft are getting most of their £££ from this
c) Google Cloud 5%ish
Container
Mini VM > runs individual apps
Group of containers is managed using Kubernetes (open source)
Function as a service
Individual methods which you can call from cloud
Structure of an application
.NET
old, huge, cumilative libraries for all Windows
.NET Core
new, streamlined, valid on: Linux, Mac and Windows
.sln
xlm file, with all the names of all the projects
'contatiner' no function of itself
just to hold multiple projects
.csproj
meta data for individual projects
Program.cs
Has the actual code
class Program{
public static Main(){
//Code goes here
}
}
To build a program with C# or dotet you need
CLI Common Languge Infrastructure
Rules for language
CLR Common Language Runtime
program runs in this enviroment
Garbage collector
Reclaims memory when you are finished with an object
CSC C Sharp Compiler
Turns .cs text into a .exe
CIL Common Intermediate Language
Half-Compiled Code
Assembly language ish
CS(raw code) > CIL > CRL
Tool called 'ILDASM' > inspect .exe and view CIL compiled code
Traditional computing has been linear programming where code starts at line 1 and finishes at the end.
OK but when GUI was invented, screen object appeared.
Button
Click event
Method/Function (Event Handler)
OBJECT EVENT METHOD (CODE)
An object looks like
{
id:1 field:value (key/value pairs)
name:bob
dob: "10/10/2001"
likes: {"strawberries", "pizza"}
}
Array [1, 2, 3]
String "Some Text"
Number
int
double 64 bits / float 32 bits / decimal types 128 bits
Class
Template/Blueprint for creating an object
e.g.
class Mammal{
int height, weight, length;
string type;
}
var m01 = new Mammal();
m01.height = 10;
m01.weight = 9999;
m01.length = 999999;
m01.type = "snek";
static void Main(string[] args)
{
var dog1 = new Dog();
dog1.Age = 10;
dog1.Height = 50;
dog1.Name = "Bob";
//Console.WriteLine("Hello World!");
Console.WriteLine($"The dog's name is {dog1.Name}, age {dog1.Age} and height is {dog1.Height}cm.");
Console.ReadLine();
}
class Dog
{
public string Name;
public int Age, Height;
}Methods are functions
they can be called to get something done
e.g. Lets grow our dog
Grow()
{
Age = Age + 1;
Height = Height + 10;
} static void Main(string[] args)
{
var person01 = new Person();
person01.name = "Fantasia";
//person01.NINo = "stuff"; Doesn't work;
person01.SetNINo("asdfghkjl");
Console.WriteLine($"{person01.name}'s NINo is {person01.GetNINo()}.");
}
class Person
{
private string NINo;
public string name;
public string GetNINo(){return NINo;}
public void SetNINo(string newNino){this.NINo = newNino;}
}Class
Fields
in a class, Fields tend to be private.
camelCase
OR
_camelCase
Properties
tend to be public
PascalCase (ThisIsAPublicProperty)
get; / set;
class Program
{
static void Main(string[] args)
{
var rabbit = new Rabbit();
rabbit.Name = "Cute01";
rabbit.Age = -10;
Console.WriteLine(rabbit.Age); //Comes out as 0 (default int value)
}
}
class Rabbit
{
private int _bloodType;
private int _age;
public string Name { get; set; }
public int Age {
get
{
return this._age;
}
set
{
if(value >= 0)
{
this.Age = value;
}
}
}
}Array has a FIXED size
List written
List<int>() has a variable size
Can be used to add items to a list
Methods in more Detail
convention
name is PascalCase void DoThis()
Parameters
are passed in void DoThis(int x, string y){}
return
passed out string DoThis { return "hi"}
optional
passed in void DoThis(int x = 1000){}
pass in but if missing set value to 1000
out parameters pass out void DoThis(intx, y, out int z)
Tuple
Fancy new variable
(int x, string y, bool z)
This is now a custom data type
static void Main()
{
//method INSIDE method
void DoThis()
{
Console.WriteLine("I am doing a thing");
}
//to call the method
DoThis();
DoThisToo();
MulitplyNumbers(5); //gives 500
MulitplyNumbers(5, 1000); //gives 5000
OutParameters(2, 5, out int a); //a = 2 * 5
var output = Tuple();
Console.WriteLine(output.x, output.y, output.z);
}
static void DoThisToo()
{
Console.WriteLine("I am doing a thing too");
}
static void MulitplyNumbers(int y, int x = 100)
{
Console.WriteLine(x*y);
}
static void OutParameters(int x, int y, out int z)
{
z = x * y;
}
static (int x, string y, bool z) Tuple()
{
return (2, "Yo", true);
}Comment: ctrl + K + C
Uncomment: ctrl + K + U
[TestCase(1000, 20)]
public void TestRabbitExplosion (int popLimit, int expectedYears)
{
var actual = just_do_it_11_rabbit_explosion.Rabbit_Exponential_Growth(popLimit).ToTuple().Item1;
Assert.AreEqual(expectedYears, actual);
} class Mercedes{
private in _privateField; //ENCAPSULATION field (private)
public string Name{get;set;} //ABSTRACTION property (public)
public void DoThis(){} //method: Verb : Action Code
public Mercedes(){} //Constructor : same name as class
var instance = new Mercedes(); //instance is a new object from the class
}Class is a template for new objects
Normal class is a CONCRETE class because we can create real objects/instances from it.
class Holiday{
public void TravelPlans(){}
public void PlacesToVisit(){ cw("This list is now complete")}
public void Activities(){ cw("All activities planned out")}
//|---> CODE IMPLEMENTATION <---|
}One method (TravelPlans) has no code implementation
This method is an abstract, because it exists but has no code body
changes made:
public void TravelPlans(){}
public abstract mvoid TravelPlans();
If one method is abstract then the class has to be abstract too.
class Holiday{
abstract class Holiday{
One method has no code implementation
It exists but has no code body
public abstract void TravelPlans();
Solution is to derive Sub-Class and inherit from abstract class
PARENT : ABSTRACT
CHILD :
abstract public class Holiday
{
public abstract void TravelPlans();
public void PlacesToVisit()
{
Console.WriteLine("Visiting Vienna, Salzburg");
}
public void Activities()
{
Console.WriteLine("Skiing, Walking, Fishing");
}
}
public class HolidayWithTravel : Holiday
{
public override void TravelPlans() { Console.WriteLine("By train eurostar, then plane, then car"); }
}When dealing with security, it might not be a good idea that people can inherit from a secure class but then introduce vulnerabilities.
RealWorld
Car engine : seal inside secure combustion chamber / chassis so amatuers dont mess with the engine and cause accidents.
CPU : Discourage overclocking
Coding
```cs
sealed class Security{
//Cannot inherit from this
}
```
String is a sealed class with lots of methods liek this one
```cs
static void Main(string[] args)
{
string x = "Hello World";
if (x.StartsWith("Hello"))
{
Console.WriteLine("World");
}
}
```
Imagine we want to build our own
```cs
public static class
{
public static void Amazing ExtraStringMethod(string s)
{
s = s + "String to add"
}
}
```
3 areas of learning
Console : MOST LEARNING HERE
WPF : Provides a screen where we can palce objects
Goal:
1) Busioness interface
2) Canvas: Simple images for a game (Crude)
Websites : Focus on business style application
Functioning data
1) ASP Regular Website
2) MVC Website
WPF is Windows Presentation Foundation
xml skeleton for gUI
C# code behind it
XML
```xml
<root>
<row>
<col attribute="dataherealso">data</col>
</row>
<row>
<col attribute="dataherealso">data</col>
</row>
<row>
<col attribute="dataherealso">data</col>
</row>
<row>
<col attribute="dataherealso">data</col>
</row>
</root>
```
Microsoft loves xml
Everyone else loves JSON
class Myclass{
private int _hideMe; //field (Encapsulation)
public string NAme {get; set;} //property Abstraction
public void DoThis()
{
}
}
abstract class Idea{
abstract void DoThis(); //No Implementation
}
class SolidThoughts : Idea{
override void DoThis(){}
}
ABTRACT CLASS > CANNOT INSTANTIATE
CONCRETE CLASS > CAN INSTANTIATE
car m = new MyClass();
Polymorphism
Parent : virtual interfa
Child : override (optional)
Abstract
Parent : abstract
Child : override (Mandatory)
Inheritence
Parent : Child
Access Modifiers:public, private, protected, internal
public
See from any other class
private
Hidden inside the class
protected
hidden inside a class and all child classes
internal
within the compiled exe. visible in this scope.
```cs
class Myclass{
private int _hideMe; //instance
public string Property01 {get; set;} //instance
public void Method01() //instance
public MyClass(){}
{
var m = new MyClass();
m = instance;
m.Property01;
m.Method01();
Math.PI;
Math.Random();
Math.Round();
STATIC MEMBERS ATTACHED DIRECTLY TO THE MATH CLASS
'
clas MyClass{
static public int Property01{get;set;}
static public void DoThis(){}
}
MyClass.Property01;
Myclass.DoThis();
```
Mind picture
User (instance) with shopping basket
static count of total items in stock
Relational Databse using Structured Query Language
Microsoft MSSQL (paid product)
Free MYSQL
Relatiobnal datgabases have
Tables
ID
Fields
User
UserID
UserName
Category
CategoryID
CategoryName
We can crate relationships
USer
UserID
UserName
CategoryID; //Foreign key
ID (IDENTITY) > Unique, Auto-Increment to Highest Value
Today
Basic SQL
Create a database
rabbit tables
Entity
C# > hook into the database
View, update rabbits
SQL Commands
View > Server Explorer. Data conection, Add
(localdb)\mssqllocaldb
View > SQL Object Explorer
Gives access to the local computer using sql server
Files called ....mdf micrsoft Datavase File
Stored in C:\Users\%username%\folder
Connecting to a database
Microsoft can connect directly to a database using Entity Framework
EF6: Framework
EFCore : Lighter / open source
If we being using EF6, there is more supprt, so its easier to get going
New Console App(Framework)
Add entity
Connect to database
View Rabbits
NEw WPF Just_Do_It_12_Rabbit_Explosion using .NET Framework
Add 2 text boxes and an ADD button
Add entity
When you click the ADD button
ADD A NEW RABBIT
DISPLAY A NEW RABBIT PICTURE FOR ONE SECOND
Create a TEXTBLOCK and do a for each loop to output the rabbit data into this text block
Agile
SCRUM
Sprint
1-4 weeks focused work
Goal of a sprint
To implement a new feature
Called a release
New increment of a version
Breaking change 1.0
2.0
3.0
Version Increment 1.1
1.2
1.3
3 Pillars of SCRUM
Transparency
Inspection
Adaptation
Agile Manifesto
people over processes
Working software over documentation
Collab over negatioation
SCRUM Roles
SCRUM master
admin, focus/flow, remove blockers
SCRUM Dev
Develop stuff
3-9 people, self organising
Product Owner
Owns backlog and lease with customer
BackLog
To do list of project
Sprint backlog
mini to do list for just this sprint
Waterfall Good for fixed/small projects that are unlikely to change
Traditional Model
REquirments
Analysis
Design
Build
Test
Release
Maintain
Document
V-Model
Adding testing to each stage of waterfall
For critical grade systems
Life is at stake
Unit testing
Test individual units/modules of code at the smallest level
intergration testing
Join modules together
system testing
Testing overall system
UAT User acceptance testing
User validates that the code meets the aggreed list of requirements
Feasability study
Initial guidance for the client
Techinically
Can we do it?
Finacial
Can we afford it/will it make money?
alpha release
Initial release, often by invitation only.
Typically journalist, specialists, stakeholders
beta release
Public testing, looking for feedback from public, not final version. Customers get early access/free game
Regression testing
Ensures that when you build a new feature or fix a bug it doesnt break existing code
White box
Look for logical errors in code.
code line by code line
Black Box
Input outout only.
Know nothing about the code
JIT just in time
Production line
Minimise waste
24/7 processes
RGR Testing
Red
Build tests that will fail
Green
Write code to pass the tests
Refactor
Optimise/maintain
Minify
Make code as small as possible to save space
WorkFlow
Work flow for continuous
Limit active work in progress
Few things in dev at a time
Fields
Member variable of a object/class
Usually private
Properties
Public access variable with a get and set method of an object/class
Class
Blueprint for an object/a collection of methods
Method
A small function (used for modular code)
PascalCase
Constructor
Create a new instance with minimum work
Overload
Same method
different parameters
Abstract Class
Class with one or more abtract methods
CANNOT instantiate an abtract class
Have to derive a child class with implements all methods
THEN you can instantiate
Abstract Method
Method with no body
Cocrete class
standard class
standard methods
CAN instantiate
Polymorphism
Inheritence with optional overide
Encapsulation
Private members within a class
Members:
Something that belongs to a class
Access modifiers
Private only in class
public anywhere
protected Parent and children
Internal within exe/dll
Inheritance
Children can inherit properties from parent
Parent : Child
Base : Derived
Abstraction
You use public properties to interact with encapsulated members
Abstract class
Class with one or more abtract methods
CANNOT instantiate an abtract class
Have to derive a child class with implements all methods
THEN you can instantiate
Abstract method
Method with no body/implementation (must be overwritten)
Abstract (dictionary)
Vague. Concept. Not tangible.
Abstracted out of a situation:
Made distant from the complexity of a situation
Abstract as a pillar
You use public properties to interact with encapsulated members
Struct is a mini class
only has fields which are fully public and any methods are fully public
Stored in fast memory of computer called the stack memory
Like primitives > integers, char, boolean, bytes
e.g. struct Point(int x, int y)
Arrays and collections
Arrays are a fixed size
Colections are variable sized
whwen reading and writing data the comp will map ram address to each array member and will go straight ti the memory address when looking at it
Arrays in memory
every cell has a a unique alloccated memory address
IEnumerable => means can count numerically over the array
Collections
Generics <T> T = any data type
int, string, char, MyClass
List<int>
List<Rabbit>
List<Customer>
List<int>
Index value like an array
Insert or remove items anywhere in the list
Queue<int>
No index, cannot get items out of the middle
FIFO, first in first out
Enqueue(add new person to the back of the queue)
Dequeue(take first person)
Peek(check first item)
Contains(boolean does the queue contain ...)
Uses: Printing, Email, Batch processing.
Stack<int>
Run an app
First method is called main
Stack is used to order running code
Every method is frozen apart from the top method with is active
Peeling off the stack => Finished
All held memory is discarded when a method is peeleD
LIFO
Last In First Out
Methods
Push
Push new item on top
Pop
Remove top item
Peek
Same
Contains
Same
Dictionary<TKey, TValue>
TKey must be unique
ArrayList (object)
List of objects
Any type goes
Hashset<int>
Fast but has no order (i.e. no index)
Has unique values but has no index
LinkedList<object>
LINQ is a special language is a special language generated by Microsoft to read databases.
LINQ has two types
from c in customers
where c.City = "Berlin"
select c
customers.Where (c => c.City == "Berlin");
Microsft have their own test database
Northwind Business database with customers
Adventure Works
For
Useful for when we know how many loops we need
Good for arrays because we get an index for each loop
for(i = 0; i < x;i++)
{
}
ForEach
Looping through a Collection
ForEach(element in Collection)
{
action
}
While
Loop until a condition is met
May never execute
while(x < 10)
{
action
}
Do...While
Loop while a condition is true
executes a minimum of one time
do
{
}while(x < 10)
Break
Useful for avoiding nested loops
Breaks out of loops completely
for(i = 0; i < 10;i++)
{
if(i == 5)
{
break; //Breaks out of loop
}
}
//Nested
if(condition)
if(othercondition)
{
if(otherothercondition)
{
}
}
}
//Using break
if(!condition)
break;
if(!othercondition)
break;
if(!otherothercondition)
break;
Continue
for(i = 0; i < 10;i++)
{
if(i == 5)
{
continue; //continues to next loop
}
}
1.Dev branch
2.Make Change + push
3.Set new origin > dev
4.Lock Master and require one pull approval
5.Add colaborators
6.Add approvers for this pull request : send for approval
7.Approver get email check code and approve/deny with comments
Check the end from the beginning
The web is so exciting
theres lots to explore
HTML = Hyper Text Markup Language : Provides skeleton for your page
```html
<html> <p> This is a paragraph </p> </html>
<tag>
<img src="html..." width="200" height="300" /> src is the attribute of the tag
```
```html
<html class="gr__">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head>
<body data-gr-c-s-loaded="true">
<title>Sample Page</title>
<style>
/*CSS styles the page*/
title {
text-align: center;
}
body {
background-color: #285B80;
color: black;
font-family: Verdana, Geneva, Tahoma, sans-serif;
font-size: 1.2em;
}
nav#mainNav {
background-color: #4E6B80;
margin-left: 15%;
padding: 3vh 2vw;
}
nav#mainNAv li {
list-style: none;
display: inline-block;
}
</style>
<script>
/*JavaScript makes things happen*/
</script>
<h1>Title </h1>
<h2>Title 2</h2>
<!--Comment-->
<nav id="mainNav">
<ul>
<li>
<a href="#">Home</a>
</li>
<li>
<a href="#">About</a>
</li>
<li>
<a href="#">Contact</a>
</li>
</ul>
</nav>
<div>
<p><strong>DIV is a division on a page</strong></p>
</div>
<header>Sections are: header</header>
<section>Section</section>
<aside>Aside</aside>
<footer>Footer</footer>
<footer>asdf</footer>
<style>
div.box {
background: #4E6B80;
margin-left: 10%;
padding: 10vh 10vw;
width: 10vw;
height: 10vh;
margin: 2vh;
display: inline-block;
display: flexbox;
}
div.BoxContainer {
margin-left: 10%;
border: 1px solid black;
}
</style>
<div class="BoxContainer">
<div class="box"> here is a box</div>
<div class="box"> here is a box</div>
<div class="box"> here is a box</div>
<div class="box"> here is a box</div>
<div class="box"> here is a box</div>
<div class="box"> here is a box</div>
</div>
</body>
</html>
```
Building raw from html can be very time consuming. Its much better to find an amazing template online and use that.
Bootstrap also provides good ways to get started quickly on a website
prov-ides all code for free and you just drop the code in
javascript took over te web because netscaoe navigator invented it but everyone adopted it
today javascrit powers most uf not all of our breowsers
but smart peaople from google took javasctioe out of the browsers and made it to run standalone without the browsers
CALLED NODEJS
When using node js we can refrence existing libraries.
to install them use
npm install <library name>#
global install
npm install -g <library name>
Then use the library with
var myVariable = require('<libraryname>')
var http = require('http')
ReactJs builds a virtual webpage then displays it as a real web page
React can just update the bits which are changed, making dynamic pages faster
1) SQL
Tables/Relationships
2) CRUD app
Console Version
WPF Version
3) Create 1000 objects
one using (var db) READ
loop though and read after
Time it
1000 using (var db) READ
loop through and read while looping
Time it
4) Canvas
Image move on wpf finish
5) Report timing results using
csv to excel
something to word
Classes
Concrete class
Means we have the
class
{
Fields
Properties
Methods
} (All complete so we can instantiate with the NEW keyword which calls the constructor method)
Abstract class
abstract class
{
} (An abstract class is a class with at least one method that has no body.
An abstract method is a mrthod with no implmentation.)
Interface Class
An interface is a fully abstract class, with absolutely no body of code in its methods
interface IDoThis{
(((abstract))) void DoThis();
} (((abstract is implied not stated)))
Parent Abstract class
Child Abstract Class (Can only be a child to one parent)
Child can also not just inherit from one parent, it can also implement or use many interfaces.
E.G.
Parent Abstract Person{} //Abstract
Child User : Person{} //Concrete
Child User : Person, IuseThis, IUseThat{} //Implement 2 interfaces
interface IUseThis{
void IDoThis{};
}
interface IUseThat{
void IDoThat{};
}
In the user class we have to build or implement code for these interface mthods IDoThis and IDoThat.
Mind picture is that each individual will use a tool in a slightly different way.
Interfaces are usefiul in large apps cause the create standardisation of how classes will have expected behaviour
E.g.
int.ToString();
char.ToString();
child.DoThis();
child.DoThat();
##Background Terms
CPU MultiCore ie several CPUs joined together
One CPU: Process info in threads
Multi-core: Can ignore this as a developer but now we can ignore it and let tassks handle it
Process is an exe or dll file. ACtually DLL files tend to be dormant 'libraries' of code which get used or 'refenced'. So actually on your comp it's the .EXEs which are executables whichc run your applications. They can refrence DLL libraries but it's the EXE which shows up as a runing process.
Task List
get-process
taskkill -pid 123456
Thread : set of instructions sent in a batch to cpu for processing
Application : runs on user request after user log on
Service : Runs on system request after system boot : can be ok to run whether or not a user is present
Threads
Are a very detailed develpoer tool to have very fine control over background threads created.
It's a lot of work.
Tasks
Tasks are a wrapper over threads. Abstract the programmer away from the hard work of creating and managing threads.
Tasks are background processes. We hand all control over the running of eack task to the OS. As a developer we have no control over which tasks runs when.
Common use:
Serial : Order matter
Parallel : Order is immaterial (does not matter)
Scripting > Linear programming
Graphics > Screen Objects
Event Driven Programming
#<Button x:name="Button01" Click="DoThis"> Main(){
private void Button01_Click(Object sender, EventArgs e)
//sender : Object initiating the event
//Event Args
}a) Trivial Example
b) OOP Example
1. Event can trigger on eor more methods. Dont declare method directly but via an agent type which will call named methods.
Delegate is a pointer object which will point to one or more methods
Declare delegate > Creates a fixed structure for permitted method in/out parameters
delegate void MyDelegate(); Pointer to methods but only methods matching this form can be part of a delegate object
YES void DoThis(){}
YES void DoThat()){}
NO int AlsoDoThis(){return -1;}
2. Declare an event but also specify the in/out patameters for any methods which will be called
public event MyDelgate MyEvent;
3. Attach methods to our events (must match in/out structure)
MyEvent += Method01; //Add
MyEvent += Method02;
MyEvent -= Method01; //Remove
Web is exciting
Check out
BLAZOR which is C# nativley running in browser
APIs
Websites are for human consumption
Built with
HTML - Structure
CSS - Colour, Animations
JavaScript - Programming
API - Application Programming Interface - For machine consumption
Simply returns data in the form of
1. JSON
json
{
"field":value,
"field":value
}
[
{
"field":value,
"field":value
},
{
"field":value,
"field":value
}
]1. XML
<rootElement> <>, Tag, Element
<item length="1"> Element with Attribute (length) and Value (1)
<field otherValue="admin">Value</field>
</item>
</rootElement>1. Northwind
2. Entity Framework
3. Scaffold API from scrathc with hardly any work
Model
Database Item > C# Class matches database Table
Northwind Customers > Class Customer
View
Display of data to the end user : HTML/CSS/JavaScript + server-side data fed into page (translated into HTML/CSS/JavaScript)
Server Client
C#/Node/PHP/Java/Python/Ruby
Render
Translates raw data
into a form suitable
for viewing ie. HTML ==> Client for display
Controller Look at URL to make sense of it
https://www.mydomain.com/controller/action/id
/customers/Get/ Get without id = Get all
/customers/Get/ALFKI Get with id = Get id
/customers/Post/ Post with no id = NEW Customer
/customers/Post/id Post with id = UPDATE
/Put/id Same as Post with id
Customer
GET = Request is visible in URL
POST = Request is inside web page data
Controller:
1. Analyse URL
2. According to instructions in URL, go and get relevant data from Model
3. Send that data to a VIEW PAGE which displays the data
MODEL : DATA
CONTROLLER : TAKE REQUEST AND RETURN DATA TO VIEW
VIEW : DISPLAY
Microsoft is stringly pushing .NET Core
Lets use it to read a database
Goals
1. Code first approahc to build our code and from this to create a database
a. SQLSERVER
b. SQLite
2. Seed data from C# ie create a new database with new data
3. Create API
.Net Core 2.1 Web App with API
Install libraries
Traditional HTML web pages looked like:
HTML Layout
<div class="navbar"><!--menu--></div>
<div class="main"><!--main content--></div>
<div class="footer"><div>HTML5 Layout
Semantic tag: sam as div (divison of a page) but just has meaning related to placing and content on a page
HEADER
NAV Nav bar
SECTION
ARTICLE
ASIDE
FOOTER
Assistive tech would sometimes use these to help people who need it.
e.g. Screen readers
e.g. <img alt="" title=""/>
alt image displayed if origianl failed to load
title is displayed on hover and also read out by screen reader
CSS
<button class="buttonTypeRound"/>
<style>
.button{
border-radius: 5px;
}
</style>
1. FlexBox
Useful for 1d arrangemtn of items eg navbar or picture gallery
2. Grid
Set varying colum widths to fied/auto/match content etc
Also sssame for rows
Good for lahying out responsive latout and placing elements with minimum og fuss. Good for centering items easily within page or grid box.
a) Flexboxes
Rebuild a couple of FLEXBOXES note: can set both horizontal or vertical.
Check phils showcase for egs.
b) GridBoxes
Got a grid eg in html intro repo
Build a webpage using grid laypout structure
Put in three features which can be interacted with using javascript
Push your website on the internet for free and connect it via github with automatic deployment on change (ie git push)
build local
push to github
deploy to netlify
change local
push to github
automatic redeployment
BurnUp: list of tasks done
BurnDown: list of tasks to be done
Theoretical overview of good programming principles.
Becomes more important on larger projects where up-front theoretical thinking and good practise can save a ton of re-factoring work later on.
S = SINGLE RESPONSIBILITY ie a class should relate to one object only
E.G.
class Rabbit GOOD
class Kitchen BAD Too vague as different, mutually exclusive subtypes
KitchenOpenPlan Mutually exclusive so use these
KitchenClosed
O = OPEN / CLOSED
Open for EXTENSTION (i.e. not sealed)
Closed for MODIFICATION (dont mess with your original work)
class A-Class dont modify if possible
class ModelA13 both modify original parent
class ModelA14
L = LISKOV
Okay to replace child with parent instances
I = USE INTERFACES
keep interfaces small
use one method per interface
E.G.
IEnumerator : GetEnumerator (countable list with numeric index) : one method only
D = DEPENDANCY : Depend on Abstract Classes at top of your structure
Stack Primitives / Value Types / Pointers Fast Instant disposal
Heap Reference Types Slower Garbage collection at intervals
SQL Theory
4 Categories
DML Data Manipulation Language
Basic Queries : SELECT, INSERT, UPDATE, DELETE (CRUD operations)
DDL Data Definition Language
Create data structures ie DAtabase/Table
CREATE/DROP - database and table ie add new or remove completely
ALTER table ie add key/column
TRUNCATE remove
DCL Data Control Language
Permissions GRANT / REVOKE
TCL Transaction Control Language
Group of transactions TOGETHER
1. COMMIT (all of the transactions in the group as a whole) e.g. atm withdrawl is either all commit or nothing
2. Rollback to a given point e.g. start of transaction group
3. SAVEPOINT : midway point og saving data progression throughout a series of transactions
use db01 /*bring into scope*/
go
drop d01 /*risk of exception if no db present*/
go
drop database if exists db01;
go
create database db01;
goInt Tinyint Bit 0,1,null Char(5) Fixed width IE CustomerID = 'ALFKI' Varchar(50) Variable wiodth up to 50 max Nvar/Nvarchar Date/Time/DateTime Blob/Binary Binary Large Object
??? Float ??? Decimal
#meta data about your table
Runs 'containers' which are mini virtual machines
Virtual Machine > 10GB > has kernel which is very large
Container > 2GB max, often much less
1. Pull container from internet conatining SQL server
2. Connect to it and run SQL Server
3. Talk to Northwind databse on that server
# get image
docker pull kcornwall/sqlnorthwind
# run image
docker run -d --name sql -p 1433:1433 kcornwall/sqlnorthwind
# list all images
docker ps -a
# start/stop
docker start sql
docker stop sql 1. Lightweight: Azure Data Studio
2. Heavyweight: SQL Server Managment Studio
UPDATE mytable set name='fred' where id=2;
DELETE FROM mytable WHERE id=2;
```sql
SELECT TOP 10 FROM CUSTOMERS;
```
AND OR
<> or (NOT EQUAL TO)
> < >= <=
```SQL
SELECT country FROM Customers ORDER BY country
SELECT distinct country FROM Customers ORDER BY country
```
```SQL
#contains 'abc'
like '%abc%'
# start
like'abc%'
# end
like'%abc'
#does not contain
not like '%abc%'
```
SELECT * FROM Employees WHERE region IN ('wa', 'bc'); SELECT * FROM products where unitprice between 10 and 20;SELECT AVG(UnitPrice) as 'Average Price', MIN(UnitPrice)as 'Minimum Price', MAX(UnitPrice) as 'Maximum Price' from Products substring();
substring(); charindex();Order by only works for fields that exist initially, but not on cumilative fields
So we can find the sum of all units in stock per product category but this field does not exist initially so we cant order by this field
For cumilative fields
i.e. SUM/MAX/MIN/AVG/COUNT
We use
GROUP BY (selecting into batches)...
HAVING (same as order by)
Order Matters
SELECT DISTINCT FROM WHERE
GROUP BY ... HAVING ...
ORDER BY...
INNER JOIN = LEFT JOIN
table1 table
table1id table2id
Aims to ensure the integrity of data within a data base
i.e. all of the relationships make sense and all of the data is current and can be found quickly with the right searches
No duplication of data ect.
One field should hold one item of data ONLY
e.g. two mobile number not two
ATOMIC
As smol as possible
i.e. one unit of data per cell
All keys depend on the primary key
No keys should have any inter-dependant relationships with each other
e.g. Name, Address, Postcode, City, County
In theory, the city and the county, actualy are related
Instead
Name, Address, Postcode, City
County
City1
City2
(This example is usually ignored in practise)
Query within a query: useful for large, long queries.
--Find customers with no orders
select ... from ... where (select ... from...)IDENTITY (1,1) Autoincrement starting at value 1 and jump by 1 each time
IDENTITY AutoIncrement
PRIMARY KEY CLUSTERED : Only one per primary key
We can build a connection string
SQL db are huge
Install is complex
Mobile phones cant communicate very easily with local SQL database.
SQLite hoolds data locally on any small device. Compatible with Unity, IOS, Android etc.
./sqlite3 //check working okay
./sqlite3 TestDatabase //to create
Within SQLite Environment
.databases //Lists all databases
.tables //Lists tables
int integer
varchar
text
real decimal
create table testTable(id int, name varchar(10));
insert into testTable values (1, bob);
select * From testTable;
create table Students(
StudentId integer primary key,
Name varchar(50)
);
insert into Students (Name) values ('Mr. Sparta');
SELECT * FROM Students;
./sqlite3 Northwind.db < Northwind.sql #Get this file from internetdotnet new console
dotnet new web
dotnet new mvc
dotnet run
dotnet build
dotnet publish
dotnet add package <<name>>
Newtonsoft.json
Microsoft.EntityFrameworkCore - 2.1.1 //Stable versions
Microsoft.EntityFrameworkCore.Sqlserver
Microsoft.EntityFrameworkCore.Sqlite
Microsoft.EntityFrameworkCore.Design
MyConsoleApp.exe
=> Get data from libraries in another palce i.e. myLibrary.dll
/Root/
/Library/
/bin/debug/library.dll
/App/
/bin/debug/
BLAZOR > c# in browser
So far we have used
Entity Databse First
I.e. Create database and pull entity from this
Creates the EDMX structure (visual database relationships)
.tt class structure
We are going to now use Entity code first
I.E.Create models (Customers.cs, Product.cs)
Create a DbContext to talk to the database
Create connection string (location of databse)
Also Optionally
Create migrations (changes to our code) which can in turn cause changes to the database.
Create migrations (changes to our code) which can in turn cause changes to the database.
Seed databse with raw data from our C# code.
Note: Many companies with LEGACY CODE are using .NET Framework
But : Many are moving to .NET Core
Plus : .Net Core work is EASIER IN FRAMEWORK
We can use this in two ways:
1. Easier to get started, Code first from database
1. Create SQL
2. Create DB with data
3. Pull into project
2. Harder
1. Create models
2. Push and crate database
- From scratch initially
- Then update as you go along
We run two commands only
NUGET
add-migration Initial
add-migration AddDateField
update-databse
POWERSHELL
add migration