developer-roadmap/roadmaps/sql/content/not-null@M4M_-vjM9GNy0NmXZneDA.md

NOT NULL Constraint

The NOT NULL constraint in SQL ensures that a column does not accept null values. When a column is defined with this constraint, every row in the table must have a value for that specific column. Attempting to insert or update a row with a null value in a NOT NULL column will result in an error, maintaining data integrity by preventing missing or undefined entries.

Visit the following resources to learn more:

• @article@SQL IS NULL and IS NOT NULL
• @video@NOT NULL Constraint