title: SQL not updating table also adding old table to new one
body: <p>it's my first time using SQL, I've followed the syntax but it doesnt work..</p>
  
  <pre><code>use cw312;
  CREATE TABLE pet (
  name VARCHAR(20),
  owner VARCHAR(20),
  species VARCHAR(20),
  sex CHAR(1),
  birth DATE,
  death DATE
  );
  Insert into pet values ('Fluffy','Harold','cat','f','1993-03-04',NULL),
  ('Claws','Gwen','cat','m','1994-03-17',NULL),
  ('Buffy','Harold','dog','f','1989-05-13',NULL),('Fang','Benny','dog','m','1990-08-      27',NULL),
  ('Bowser','Diane','dog','m','1998-08-31','1999-07-11'),
  ('Chirpy','Gwen','bird','f','1998-09-11',NULL),
  ('Whistler','Gwen','bird','f','1997-12-09',NULL),
  ('Slim','Benny','snake','m','1996-04-29',NULL),
  ('Puffball','Diane','hamster','f','1999-03-30',NULL),
  ('Daddy', 'Jennifer', 'dog', 'm', '1970-03-30', NULL),
  ('Major', 'Margaret','cat', 'm', '1993-03-30','2000-04-30');
  
  UPDATE pet SET species = 'dog'
  WHERE owner = 'Margaret';
  
  
  
  
  DESCRIBE pet;
  SELECT 
    *
  FROM
  pet;
  </code></pre>
  
  <p>Why doesnt the update pet set species = dog where owner = margaret update the species to dog?</p>
  
  <p>Also every time i execute this, sql like remakes the Database and adds it to my previous version.. any idea why?</p>