SQL operators - Arithmetic, Relational, Concatenation, NULL & NOT NULL - Day8

@LearnWithRD0529 - OPERATORS - ARITHMETIC, RELATIONAL, CONCATINATION, NULL & NOT NULL.
================
CREATE TABLE sales (
sale_id INT PRIMARY KEY,
product_name VARCHAR(100),
quantity_sold INT,
unit_price DECIMAL(10, 2),
tax decimal(5,2),
sale_date DATE
);

INSERT INTO sales (sale_id, product_name, quantity_sold, unit_price,tax, sale_date)
VALUES(1, 'Widget A', 50, 12.99,3, '01-AUG-2023');
INSERT INTO sales (sale_id, product_name, quantity_sold, unit_price,tax, sale_date)
VALUES(2, 'Widget B', 30, 9.99,2.0, '02-AUG-2023');
INSERT INTO sales (sale_id, product_name, quantity_sold, unit_price,tax, sale_date)
VALUES(3, 'Widget A', 20, 12.99,3.0, '03-AUG-2023');
INSERT INTO sales (sale_id, product_name, quantity_sold, unit_price,tax, sale_date)
VALUES(4, 'Widget C', 10, 24.99,5.0, '04-AUG-2023');
INSERT INTO sales (sale_id, product_name, quantity_sold, unit_price,tax, sale_date)
VALUES(5, 'Widget B', 40, 9.99,2.0, '15-AUG-2023');
===================SESSION NOTES======================

SELECT * FROM SALES;

SELECT SALE_ID,PRODUCT_NAME,QUANTITY_SOLD,UNIT_PRICE,TAX,
QUANTITY_SOLD * UNIT_PRICE AS TOTAL_SALES,
UNIT_PRICE * (10/100) AS DISC_PRICE,
UNIT_PRICE - (UNIT_PRICE * 0.1) + TAX AS SL_PRICE,
UNIT_PRICE + (UNIT_PRICE * 0.1) + TAX AS MRP
FROM SALES;

================================================

SELECT FIRST_NAME,LAST_NAME,SALARY,COMMISSION_PCT,
SALARY * (10/100) AS PROVIDENT_FUND,
SALARY * 0.01 AS MED_INSURACE
FROM EMPLOYEES;
==================================================