title: How do I use the . properly with sql?
body: <p>I am new to sql and have a question about joining 2 tables. Why is there a <code>.</code> in between <code>customers.custnum</code> in this example. What is its significance and what does it do?</p>
  
  <p>Ex.</p>
  
  <pre><code>Select 
      customers.custnum, state, qty
  From 
      customers 
  Inner join 
      sales On customers.custnum = sales.custnum
  </code></pre>