sql - Update null values when we use Addition assignment (+=)

Question

declare @temp table
(
    Id int,
    Qty int 
)

insert into @temp values(1,null)
update @temp set Qty+=2

select * from @temp

I am trying to update the Qty column however the Qty column is null by default. So because the production database column might be null when I try to update I am getting a null value I need Qty to be 2.

Answer 1

Use coalesce (or isnull) to handle the null case.

update @temp set Qty = coalesce(Qty,0) + 2;