How to change null and empty string in sqlite?

Question

Here is my sqlite databse ,you can see some cell are null or empty string when opening with sqlitemanager.

How can i change all the null and empty string into 0 (zero) in this sqlite database ,not by hand one by one (you can do it in sqlite manager,but it is stupid to change all in one database).

Answer 1

UPDATE grade SET d3 = 0
   WHERE d3 IS NULL OR d3 = ''