SQL what is it code example

Example 1: what is sql

SQL stands for:
Structured Query Language

It's language which enables a user to create,
modify and essentially interact with a database.
As a tester we are usually using Data manipulation
language part of SQL

SQL has 2 parts:
1-DATA MANIPULATION LANGUAGE
It is used to add, retrieve or update the data.
= insert, select, update, delete

2-DATA DEFINITION LANGUAGE
It is used to create database schema and can
be used to define some constraints as well.	
=create, alter, drop, truncate

create table
create window etc.

Example 2: what is sql

SQL is a domain-specific language used in programming and designed for managing
data held in a relational database management system, or for stream processing
in a relational data stream management system.

Example 3: SQL

CREATE TABLE friends (
   id INTEGER,
   name TEXT,
   birthday DATE
);

INSERT INTO friends (id, name, birthday) 
VALUES (1, 'Jane Doe', '1990-05-30');


INSERT INTO friends(id , name , birthday)
VALUES(2 , 'APOORV' , '2000-2-2');



UPDATE friends
SET name = 'Jane Srivastava'
WHERE id = 1;

ALTER TABLE friends 
ADD COLUMN email TEXT; 


UPDATE friends 
SET email =  '203029@klsafjls'
where id  = 1; 

UPDATE friends 
SET email =  '203029@klsafjls'
where id  = 2;

DELETE FROM friends 
WHERE id = 1;


SELECT * 
FROM friends;

Example 4: what is sql

SQL is basically a programming language that lets people manipulate databases.

Example 5: how do you use sql

Our web application uses Oracle database and 
I normally write queries to do Data validation. 
For example: 
I create data from UI or I send POST request
from API then I write query to verify that
data was successfully and correctly inserted
into database. Our database consists of
many tables, so most of the time,
I need to write queries that involve joins.

CAN MENTION: Since our application has
large sets of data, data is stored into
Oracle and to another CACHE database. 
I write queries to test data that both are in SYNC(same).