title: NOT NULL constraint in DynamoDB
body: <p>I want to use DynamoDB for creating tables. We don't have to specify all the column names while creating schema in DyamoDB and only the primary key(hash key + sort key[optional]). Now if my table does have some other attributes that I want to be there for every item inserted-i.e., add NOT NULL constraint to an attribute other than the key, then how can I achieve it in DynamoDB?</p>