title: What do the *= and =* operators do in T-SQL?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/1428144/sql-what-does-mean">SQL: What does =* mean?</a>  </p>
  </blockquote>
  
  <p>I am going through some legacy code and found a query like this:</p>
  
  <pre><code>SELECT * from foo_table, bar_Table where foo_table.id *= bar_table.fac_id
  </code></pre>
  
  <p>What does the *= operator do?</p>