Computer Science for IGCSE & O level - Databases (Section 5 - No. 10)
What is the role of the `NOT NULL` constraint in a database?
Allows a column to contain only unique values.
Ensures that a column cannot have a null value.
Sets a default value for a column.
Defines a relationship between tables.
Giải thích
The `NOT NULL` constraint ensures that a particular column must always have a value.