title: SQL Server : allow 3 letters and 4 numbers in a varchar(7) column
body: <p>I'm trying to create a constraint for a SQL Server table in order to allow only 3 letters and 4 numbers on a single <code>varchar(7)</code> column.</p>
  
  <p>Example: <code>ABC1234</code></p>
  
  <p>Can anyone help?</p>