title: SQL Compute Default Value Column
body: <p>I have 5 Column in my table transaction</p>
  
  <pre><code>Debit, Credit, Rate, CompanyDebit, CompanyCredit
  </code></pre>
  
  <p>The question :
  How will I add default value for <code>CompanyDebit</code> &amp; <code>CompanyCredit</code> using  the following formula:</p>
  
  <pre><code>CompanyDebit = debit * rate
  CompanyCredit = credit * rate
  </code></pre>