title: Find character sequence at specific position in string
body: <p>I need to use SQL to find a sequence of characters at a specific position in a string. </p>
  
  <p>Example:
  atcgggatgccatg</p>
  
  <p>I need to find 'atg' starting at character 7 or at character 7-9, either way would work. I don't want to find the 'atg' at the end of the string. I know about LIKE but couldn't find how to use it for a specific position.</p>
  
  <p>Thank you </p>