SQL Cheat Sheet: Essential Commands for Beginners

SQL (Structured Query Language) is the backbone of database management. Whether you're retrieving, inserting, updating, or deleting data, mastering SQL is crucial. This SQL Cheat Sheet covers fundamental commands to get you started:

Basic SQL Commands

• SELECT – Retrieve data from a table
  
  
  

  
  

  
  

  SELECT * FROM employees;

  
  


• WHERE – Filter records
  
  
  

  
  

  
  

  SELECT * FROM employees WHERE salary > 50000;

  
  


• INSERT – Add new data
  
  
  

  
  

  
  

  INSERT INTO employees (name, age, salary) VALUES ('John Doe', 30, 60000);

  
  


• UPDATE – Modify existing data
  
  
  

  
  

  
  

  UPDATE employees SET salary = 65000 WHERE name = 'John Doe';

  
  


• DELETE – Remove records
  
  
  

  
  

  
  

  DELETE FROM employees WHERE age < 25;

  
  

Advanced Queries

• JOIN – Combine data from multiple tables
  
  
  

  
  

  
  

  SELECT employees.name, departments.department_name FROM employees JOIN departments ON employees.dept_id = departments.id;

  
  


• GROUP BY – Aggregate data
  
  
  

  
  

  
  

  SELECT department, AVG(salary) FROM employees GROUP BY department;

  
  

Master these commands, and you'll be well on your way to SQL proficiency!