Here's a MySQL cheat sheet with some commonly used commands and concepts:

Connecting to MySQL:

mysql -u username -p

Basic Commands:

• Show Databases:
  

  SHOW DATABASES;
  

• Create Database:
  

  CREATE DATABASE database_name;
  

• Use Database:
  

  USE database_name;
  

• Show Tables:
  

  Show Tables
  

• Describe Table:
  

  DESCRIBE table_name;
  

Data Manipulation:

• Insert Data:
  

  INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...);
  

• Update Data:
  

  UPDATE table_name SET column1 = value1, column2 = value2 WHERE condition;
  

• Delete Data:
  

  DELETE FROM table_name WHERE condition;
  

• Select Data:
  

  SELECT column1, column2, ... FROM table_name WHERE condition;
  

Filtering and Sorting:

• Filtering with WHERE:
  

  SELECT * FROM table_name WHERE condition;
  

• Sorting with ORDER BY:
  

  SELECT * FROM table_name ORDER BY column_name ASC/DESC;
  

Aggregation Functions:

• Count:
  

  SELECT COUNT(column_name) FROM table_name;
  

• Sum:
  

  SELECT SUM(column_name) FROM table_name;
  

• Average:
  

  SELECT AVG(column_name) FROM table_name;
  

Joining Tables:

• Inner Join:
  

  SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column;
  

• Left Join:
  

  SELECT * FROM table1 LEFT JOIN table2 ON table1.column = table2.column;
  

• Grouping Data:
  

  SELECT column1, COUNT(*) FROM table_name GROUP BY column1;
  

Indexes:

• Creating Index:
  

  CREATE INDEX index_name ON table_name(column_name);
  

• Dropping Index:
  

  DROP INDEX index_name ON table_name;
  

Backup and Restore:

• Backup:
  

  mysqldump -u username -p database_name > backup.sql
  

• Restore:
  

  SHOW DATABASES;
  

Remember to replace username, database_name, table_name, etc., with your actual values. This cheat sheet covers the basics, but MySQL is a rich and powerful database system, so there's a lot more you can explore and learn.