title: Substring of a specific occurence
body: <p>I have a column as varchar2 datatype, the data in it is in format:</p>
  
  <pre><code>100323.3819823.222
  100.323123.443422
  1001010100.233888
  LOL12333.DDD33.44
  </code></pre>
  
  <p>I need to remove the whole part after the first occurrence of '.'</p>
  
  <p>In the end it should look like this:</p>
  
  <pre><code>100323
  100
  1001010100
  LOL12333
  </code></pre>
  
  <p>I cant seem to find the exact substring expression due to the fact that there is not  any fix length of the first part.</p>