title: How to store part of a field value in another column in SQL
body: <p>So I'm trying to get a part of a value from a column and insert that part into another column - new column. BOTH columns are in the same table. So what i want should look something like this:</p>
  
  <pre><code>id      newColumn      oldColumn
  1       12             123 some text
  2       24             246 some text
  ....
  </code></pre>
  
  <p>I know how to get 12 and 24 using SUBSTR, but how do i enter the data for each row in the table. Should i be using self-join or something else?</p>