SQL Queries Practice Set

How to Practice Effectively

Sample Table

CREATE TABLE employees (
  id INT PRIMARY KEY, name VARCHAR(50),
  dept VARCHAR(20), salary INT, city VARCHAR(20)
);

Exercises

-- 1. Highest paid employee in each department
SELECT dept, MAX(salary) FROM employees GROUP BY dept;
-- 2. Employees earning above company average
SELECT name FROM employees WHERE salary > (SELECT AVG(salary) FROM employees);
-- 3. Count employees per city
SELECT city, COUNT(*) FROM employees GROUP BY city;
-- 4. Second highest salary
SELECT DISTINCT salary FROM employees ORDER BY salary DESC LIMIT 1 OFFSET 1;

Summary

• Practice on a real table; write the query before checking.
• Master grouping, subqueries and "second highest" patterns.

असरदार Practice कैसे करें

Sample Table

CREATE TABLE employees (
  id INT PRIMARY KEY, name VARCHAR(50),
  dept VARCHAR(20), salary INT, city VARCHAR(20)
);

Exercises

-- 1. हर department में सबसे ज़्यादा salary
SELECT dept, MAX(salary) FROM employees GROUP BY dept;
-- 2. company average से ज़्यादा कमाने वाले
SELECT name FROM employees WHERE salary > (SELECT AVG(salary) FROM employees);
-- 3. हर city के employees गिनें
SELECT city, COUNT(*) FROM employees GROUP BY city;
-- 4. दूसरी सबसे ऊँची salary
SELECT DISTINCT salary FROM employees ORDER BY salary DESC LIMIT 1 OFFSET 1;

सारांश

• Real table पर practice करें; check से पहले query लिखें।
• Grouping, subqueries और "second highest" patterns master करें।