How can you set a field to not be nullable in DB2?

In DB2, you can set a field to be not null using the following methods:

1. Specify a field as NOT NULL when creating a table: Use the CREATE TABLE statement to define the table structure and add the NOT NULL keyword after the field definition. For example:
2. The table called mytable is to be created with two columns: id, which must be an integer and cannot be empty, and name, which must be a string of up to 50 characters and cannot be empty.
3. Change the field constraints of an existing table: Use the ALTER TABLE statement to modify the field constraints of an existing table, setting the field to NOT NULL. For example:
4. Change the mytable column name to not allow null values.

Please make sure the field is not NULL when setting it as a required field, otherwise errors may occur during data insertion.