Change a column to not allow nulls

Question

So I want to change a column in my SQL Server database to not allow nulls, but I keep getting an error. this is the sql statement I am using:

alter table [db         


        

Answer 1

If you are trying to change a column to not null, and you are getting this error message, yet it appears the column has no nulls, ensure you are checking for is null and not = null (which gives different results).

Select * from ... where column is null

instead of

Select * from ... where column = null

I am adding this because it tripped me up and took a while to resolve.