Handle NULL correctly in WHERE clauses

Use IS NULL and IS NOT NULL properly

Understand NULL comparison behavior

Apply COALESCE for NULL-safe comparisons

Avoid common NULL filtering pitfalls

Build NULL-aware business logic

Handle NULL correctly in WHERE clauses

Use IS NULL and IS NOT NULL properly

Understand NULL comparison behavior

Apply COALESCE for NULL-safe comparisons

Avoid common NULL filtering pitfalls

Build NULL-aware business logic