title: Removing duplicate values in TEXTJOIN and IF function
body: <p>I'm using the TEXTJOIN function with IF: </p>
  
  <p>It works fine, but also includes duplicate values. </p>
  
  <pre><code>{=TEXTJOIN(", ",TRUE,IF(C4:C9=E4,B4:B9,""))}
  </code></pre>
  
  <p>The result I get with this formula (see the image attached) is 1, 1, 3, 4, but I need it to show 1, 3, 4</p>
  
  <p><a href="https://i.stack.imgur.com/boewX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/boewX.png" alt="enter image description here"></a></p>
  
  <p>How can I make it show only the unique values?</p>