CREATE TABLE Doctors ( doctor_id INT AUTO_INCREMENT PRIMARY KEY, doctor_name VARCHAR(100) NOT NULL, specialization VARCHAR(100), phone VARCHAR(15) ); CREATE TABLE Patients ( patient_id INT ...

Paying taxes is a requirement for individuals and businesses in nearly every community in the world, yet some people avoid giving their share. Previously, taxpayers in Egypt were responsible for ...

1️) Scalar Subquery in SELECT: SELECT e.emp_id, e.emp_name, e.salary, (SELECT ROUND(AVG(salary), 2) FROM employees WHERE dept_id = e.dept_id) AS dept_avg_salary FROM employees e; 2️) Correlated ...