title: MySql unique id for several records
body: <p>I use one table withe some casual columns such as id, name, email, etc...also I'm inserting a variable numbers of records in each transaction, to be much efficient I need to have one unique id lets call it transaction id, that would be the same for each group of data which are inserted in one transaction, should be increment. What is the best approach for doing that? 
  I was thought to use </p>
  
  <pre><code>select max(transaction_id) from users 
  </code></pre>
  
  <p>and increment that value on server side, but that seams like old fashion solution.</p>