title: Create if not exists else update tables
body: <p>I want to create table  if not exists,else update it.</p>
  
  <p>this code is for create table:</p>
  
  <pre><code>CREATE TABLE Book 
  ID     INT(10) PRIMARY KEY AUTOINCREMENT,
  Name   VARCHAR(60) UNIQUE,
  TypeID INT(10),
  Level  INT(10),
  Seen   INT(10)
  </code></pre>
  
  <p>how can I change it to support update too?</p>
  
  <p><strong>//EDIT</strong></p>
  
  <p>I mean if I add a column,only add a column...not remove last data</p>
  
  <p>If I remove a columns (for example remove TypeID INT(10) from the command) just that columns be remove...not all data</p>