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

Clearly, the table has NULL values in it. Which you can check with:

select *
from mydatabase
where WeekInt is NULL;

Then, you can do one of two things. Either change the values:

update mydatabase
    set WeekInt = -1
    where WeekInt is null;

Or delete the offending rows:

delete from mydatabase
    where WeekInt is null;

Then, when all the values are okay, you can do the alter table statement.