title: RegExp Find Numbers that have All Same Digits
body: <p>I am working with an Oracle database and would like to write a REGEXP_LIKE expression that finds any number where all digits are the same, such as '999999999' or '777777777' without specifying the length of the field. Also, I would like it to be able to identify characters as well, such as 'aaaaa'. </p>
  
  <p>I was able to get it working when specifying the field length, by using this:</p>
  
  <pre><code>select * from table1
  where regexp_like (field1, '^([0-9a-z])\1\1\1\1\1\1\1\1');
  </code></pre>
  
  <p>But I would like it to be able to do this for any field length.</p>
  
  <p>If a field contains '7777771', for example, I would not want to see it in the results.</p>