Altering a column: NULL to NOT NULL

Problem

Change column from NULL to NOT NULL in Microsoft SQL Server.

Solution

There are two steps you need to do

1. First of all, you have to set all ‘NULL’ values to some other value.

   UPDATE [Table] SET [Column]=0 WHERE [Column] IS NULL

2. After that, you can run this command to change NULL to NOT NULL column

   ALTER TABLE [Table] ALTER COLUMN [Column] INTEGER NOT NULL