What is PL/SQL?

1. PL/SQL stands for Procedural Language Extension to SQL
2. It is a Extension of SQL developed by Oracle.
3. It adds SQL capabilities of procedural programming like variables, loops and conditional statements in SQL.

PL/SQL Architecture

Physical Architecture

• PL/SQL engine processes the entire PL/SQL block of code.
• It Separate SQL statements and Procedural statements.

Simple Architecture Flow

PL/SQL Logical Architecture

• Corporates with SQL Engine.
• Enables Subprograms -> Allows re-usability of code/script like variables and functions.
• Dynamic Queries-> We can modify or create new Queries.
• Case Insensitivity
• Optimizer-> It optimizes our code for better performance.
• Enables Object-Oriented Programming
• Web Development #Extras Context Switching: When you write SQL Query in PL/SQL the PL/SQL send the query to SQL Engine and the result will be returned this operation is called Context Switching.

Pluggable Database

Introduction to React

React is a JavaScript library for building user interfaces, particularly single-page applications where you need a fast, interactive UI.

Installation

To create a new React app, use:

npx create-react-app my-app cd my-app npm start

JSX (JavaScript XML)

JSX allows writing HTML elements inside JavaScript and placing them in the DOM without using methods like createElement.

Example:

const element = <h1>Hello, React!</h1>;

React Components

React components are reusable pieces of UI. There are two types:

Base System in Computer Architecture

Refer Unit 1 FIT Notes

https://youtu.be/bWrsk0QizEk?si=6XBleKlCR-PaCF_C

Best One Shot

https://youtu.be/NY2gz_Kzc0Q?si=YburSfFaLyNTFhf0

Important Libraries

from selenium import webdriver 
from selenium.webdriver.chrome.service import Service 
from selenium.webdriver.support.ui import Select 
from selenium.webdriver.common.by lmport By 
from selenium.webdriver.support import expected_conditions as EC 
from selenium.webdriver.support.ui import WebDriverWait 
import time 
from selenium.webdriver.common.action_chains import ActionChains 
from selenium.webdriver.chrome.options import Options 
from selenium webdriver.remote.webelement import WebElement

1. webdriver

imports the webdriver module from the Selenium library, which allows you to automate browser actions like clicking, typing and navigating.

2. Service

Service is used to manage the lifecycle of the chromedriver.exe process (starting, stopping, and communication).