title: Checking composite primary exists or not?
body: <p>I have a table named <code>Basket</code> that has a composite primary key <code>CustID</code> and <code>ProductID</code>, with 1 more attribute <code>Quantity</code>. <code>@custID</code> and <code>@productID</code> are passed to a stored procedure. </p>
  
  <p><strong>I need to first check whether these 2 parameters already exists as composite PK or not, if NOT then I want to insert whole record by setting PK with parameters and increase quantity by 1.</strong> </p>
  
  <p>If the record already exist then I simply need to update quantity column by 1.</p>
  
  <p>I am having tough time in checking and inserting the bold text. 
  If someone know the solution kindly guide me please.</p>