title: SQL calculate percentage based on existing data in table and update
body: <p>I have table as below with all the fields except percentage. Based on the total Number of cases I need to calculate percentage for each case id. For easy interpretation I choose numbers as below. So the total cases for all the caseids is 100, out of which case id as 35 cases so its percentage is 35. What script can I use to get those total percentage values and update in table accordingly.</p>
  
  <pre><code>CaseID NumHighCases NumMedCases NumLowCases TotalCases TotalPerc
  1         10            20         5           35          35%
  2         5              5          5          15          15%
  3         8              12         20         40          40%
  4         3               4          3         10          10%
  </code></pre>