title: unexpected result concatenating simple strings in Sybase SQL
body: <p>I'm getting unexpected results with a very simple bit of SQL, on Sybase.</p>
  
  <pre><code>declare @mystring char(30)
  
  select @mystring = 'abc'
  
  select 'mystring = ' + @mystring
  
  select @mystring = @mystring + 'xyz'
  
  select 'mystring = ' + @mystring
  </code></pre>
  
  <p>This returns:</p>
  
  <pre><code>mystring = abc                           
  mystring = abc   
  </code></pre>
  
  <p>Why doesn't the last select return 'abcxyz' ?</p>
  
  <p>Thanks</p>
  
  <p>Bob</p>