NULL Handling

NULLs break equality, aggregation, and logic in ways most candidates cannot explain

NULLs break equality, aggregation, and logic in ways most candidates cannot explain

Category

SQL

Difficulty

advanced

Duration

25 minutes

Challenges

0 hands-on challenges

Topics covered: The Three-Valued Logic Landmine, IS NULL, COALESCE, and NULLIF, NULLs in WHERE, JOIN, and GROUP BY, NULLs in Aggregates and Window Functions, Intentional NULLs vs Missing Data: The Design Question

Lesson Sections

1. The Three-Valued Logic Landmine

   Content coming soon.

2. IS NULL, COALESCE, and NULLIF

   Content coming soon.

3. NULLs in WHERE, JOIN, and GROUP BY

   Content coming soon.

4. NULLs in Aggregates and Window Functions

   Content coming soon.

5. Intentional NULLs vs Missing Data: The Design Question

   Content coming soon.