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these commands are specific to mongo shell (mongosh command):

1. show dbs ==> shows list of all available databases
2. use flights ==> when starting to insert data in this DB, then flights db will be created on the fly.
3. db.flightData.insertOne({"name":"f1"})
4. db.flightData.find(); ==> shows all data
5. db.flightData.find().pretty(); ==> shows all data in pretty format
6. mongoDB uses BSON (which is binary json) for storing data in database.

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1. in blade template engine: {{ $x }} is equal to <?php echo $x ?>
2. behind the scenes the blade code is compiled to vanilla php.
3. it is possible to define conditional aggregate in laravel eloquent queries. for example:

suppose we have a table called requested_features which has columns named: title and status.
the status column can has three distinct values: 1.planned 2.requested 3.completed
if we want to count number of records which has "status=planned" and "status=requested" and "status=completed"
then the best solution is:

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<?php
// Attributes (AKA Annotations).
#[Attribute(Attribute::IS_REPEATABLE | Attribute::TARGET_FUNCTION)]
class CharDecoratorAttribute
{
    public function __construct(protected string $char) // Constructor Property Promotion
    {
    }

    public function decorate(Closure $fn): Closure

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Topics coming in the next edition:

• ✅ Load balancers from scratch (published on 10th of October)
• ✅ Terraform (published on 12th of November)
• HELM

Fundamentals - 208 pages (Basic package)

Building a pipeline

nginx

• Serving static content
• CGI, FastCGI, php-fpm

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---

----------------installing React---------------------

0. node must be installed on your system. when installing node, npm also get installed.
1. way1: npx create-react-app <your_project_name>

**note:
The main difference between "npm create-react-app" and "npx create-react-app" lies in how they are used to create a new React application.

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1. all python files should have .py extension.
2. interesting note: in this code, * is printed 10 time:

print("*" * 10)

3. there is two different version for python:

• python2
• python3

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Most PHP programmers have used PHP strictly in a web server environment. In such an environment, PHP is a CGI/Fast GGI or server module called and controlled by the HTTP server (usually Apache, IIS, Nginx, or similar)\

The HTTP server receives a request for a PHP-based web page and calls the PHP process to execute it, which usually returns output to the HTTP server to be sent on to the end user.

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1. create a copy from a table:
   suppose we have already a table named: orders and we want to make a copy from this table which name will be order_archived.\

   CREATE TABLE order_archived AS 
       SELECT * FROM orders

   but please note: this way does not copy some column attributes like primary key.

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Big-O time complexity:

1. big O is used to describe the performance of an algorithm. it determines how scalable an algorithm is. ==> we want to figure out how the algorithm slows down as size of arguments grows larger.

run time complexity

O(1) — Constant Time:
O(log n) — Logarithmic Time: The number of steps it takes to accomplish a task are decreased by some factor with each step.
O(n) — Linear Time: The number of of steps required are directly related (1 to 1).
O(n²) — Quadratic Time: The number of steps it takes to accomplish a task is square of n.\

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resource which I must study continously and carefully:

1. https://www.php.net/manual/en/langref.php
2. https://github.com/phpinternalsbook/PHP-Internals-Book
3. https://www.npopov.com/2015/06/19/Internal-value-representation-in-PHP-7-part-2.html
4. https://phpsecurity.readthedocs.io/en/latest/index.html