title: Keep leading zeros when joining data sources in tableau
body: <p>I am trying to create a data source in Tableau (10.0) where I am joining a table from SQL  with an Excel file. The join happens on a <code>site id</code> but when reading the id from the excel source, Tableau strips the leading zeros (and SQL keeps leading zeros). I see <a href="https://www.interworks.com/blog/skennedy/2014/05/05/how-handle-headache-leading-zeros-tableau" rel="nofollow noreferrer">this example</a>
  to add the leading zeros back as a new, calculated field. But the join is still dropping rows because the id is not properly formatted when making the join. </p>
  
  <p>How do I get the excel data source to read the column with the leading zeros so I can do the join?</p>