virgin = 0;     /* you're not a virgin anymore, sweety */

switch(value)
{
   [...]
default:
   ASSERT(**true**); // if this is triggered, something really bad is happening.
}

// Caveat implementor

在OLTP数据库事务的主要触发代码中找到:

-- This line negates the @inverseqty, which is the
-- negative of the @insertedquantity.  This works through the
-- magic of the trigger.  In fact, this code is a lot like
-- the bermuda triangle!
@negquantity = -1 * @inverseqty

 * ...and don't just declare it volatile and think you've solved
 * the problem. You young punks think you know what volatile
 * means... why in my day we had to cast it volatile uphill
 * both ways, and the code still didn't work! Whippersnappers...

//Abandon all hope ye who enter beyond this point