title: Mysql print repeated characters based on length
body: <p>What I want to do is basically print "xxxx" for "asda"
  or "xxxxxx" for "forget". The number of characters should be same.</p>
  
  <p>what I have tried in sql</p>
  
  <p>Suppose I run </p>
  
  <pre><code>select length("adsa")
  </code></pre>
  
  <p>I get <code>4</code></p>
  
  <p>and when I run this : </p>
  
  <pre><code>select repeat('x',  4);
  </code></pre>
  
  <p>I get <code>xxxx</code></p>
  
  <p>Now when I try doing this :</p>
  
  <pre><code>select repeat('x',  select length("adsa"));
  </code></pre>
  
  <p>It throws error. Where am I going wrong ?</p>