title: Check if the value of one column contains the value of another
body: <p>I have a table with java package names:</p>
  
  <pre><code>|id|pkg|
  |1 |some.long.package.path|
  |2 |com.admob.bla|
  </code></pre>
  
  <p>and a table that contains partial packages names form known advertisement frameworks.</p>
  
  <pre><code>|id|path_fragment|
  |1 |.admob |
  </code></pre>
  
  <p>How can I retrieve packages whose value for pkg contains any of the ad_frameworks.path_fragment?</p>
  
  <p>I just can't find the substring check. All I find is people using like to compare to some string literal but never for comparing columns.</p>
  
  <p>NOTE: I am using MySQL.</p>