Updating table in SQL Server

Question

I am running my query, but it does not work. The cause is the value of column is null and I'm trying to update it with a integer value.

This is my query.

The default value of sdoc is null

update expenese 
set sdoc = sdoc + '200' 
where expenese.date = '2016-03-26';

Answer 1

UPDATE EXPENESE
SET SDOC=ISNULL(SDOC,0)+200
WHERE DATE='2016-03-26'