title: how to replace NULL value during insertion in sql
body: <p>my table looks like this</p>
  
  <pre><code>+--------+--------+--------------+--------------+
  | CPI_id | Weight | score_100_UB | score_100_LB |
  +--------+--------+--------------+--------------+
  |    1.1 |     10 |          100 |           90 |
  +--------+--------+--------------+--------------+
  </code></pre>
  
  <p>while executing the insert query the table should look like</p>
  
  <pre><code>+--------+--------+--------------+--------------+
  | CPI_id | Weight | score_100_UB | score_100_LB |
  +--------+--------+--------------+--------------+
  |    1.1 |     10 |          100 |           90 |
  |    5.5 |     10 |         NULL |           93 |
  +--------+--------+--------------+--------------+
  </code></pre>
  
  <p>but NULL values should be replaced by 100.
  I also tried using trigger.I couldn't get.</p>
  
  <p>thanks in advance</p>