How to add a not null constraint on column containing null values

Question

I have a table with a column that contains a few null values. I want to add a NOT NULL constraint on that column without updating the existing nulls to a non-nu

Answer 1

ALTER TABLE table_name SET column_name = '0' WHERE column_name IS NULL;

ALTER TABLE table_name MODIFY COLUMN(column_name NUMBER CONSTRAINT constraint_identifier NOT NULL);

This is of course assuming that your column is a number but it's the same thing really, you would just change the '0' to a default value that isn't null.