title: Oracle RegExp_Like for Two Repeating Digits
body: <p>I would like to write a regexp_like function which would identify if a string consists of two repeating characters. It would only identify a string that has alternating numbers and only consisting of two unique numbers, but the unique number cannot repeat, it must alternate.</p>
  
  <p><strong>Requirement :</strong></p>
  
  <p>Regular expression should match the pattern for <code>787878787</code>, but it should <strong>NOT</strong> match the pattern <code>787878788</code>
  It should NOT consider the pattern like <code>000000000</code></p>