title: Datatype on output column not reflecting change to source item in SSIS
body: <p>Take a sqlCommand in a source item:</p>
  
  <pre><code>SELECT SUBSTRING(MKGDiagnoses.ICD9Code, 2,7) AS ICD9Code 
  FROM ...     
  </code></pre>
  
  <p>The column ICD9Code outputs a string with a length of 7 positions.
  Now change to:</p>
  
  <pre><code>SELECT SUBSTRING(MKGDiagnoses.ICD9Code, 2,6) AS ICD9Code 
  FROM ...   
  </code></pre>
  
  <p>So datatype of the column is changed to a string of <strong>6</strong> positions.</p>
  
  <p>A change like this is never reflected in the datatype of the output columns, while the datatype of the external column did change to [DT_STR] with length 6.</p>
  
  <p><img src="https://i.stack.imgur.com/MnfUX.jpg" alt="advanced editor"></p>
  
  <p>Is this expected behaviour? Is this behaviour overwritable?</p>