A dirty read occurs when one user is updating or inserting a record while a different user is reading it, but the work is not yet committed to the database, as shown in the following example.

                User A executes:
	INSERT INTO State (state, state_name, region) 
	VALUES (‘ME', 'Maine', ‘Northeast'); 
User B executes:	SELECT * FROM State; 
User B sees: state ‘ME' 
User A executes: 	ROLLBACK WORK; User B has seen data that really did not exist.