Understand how COUNT(*) includes NULL rows while COUNT(column) excludes them

Learn how SUM, AVG, MIN, MAX completely ignore NULL values in calculations

Discover what happens when all values in a column are NULL

Master COALESCE to safely convert NULL to default values before aggregation

Handle NULL in business contexts like missing bonuses and incomplete forms

Write NULL-safe aggregate queries that produce accurate business reports

Avoid common NULL traps that silently break dashboards and KPIs

Choose the right approach: filter NULL out vs treat NULL as zero

Understand how COUNT(*) includes NULL rows while COUNT(column) excludes them

Learn how SUM, AVG, MIN, MAX completely ignore NULL values in calculations

Discover what happens when all values in a column are NULL

Master COALESCE to safely convert NULL to default values before aggregation

Handle NULL in business contexts like missing bonuses and incomplete forms

Write NULL-safe aggregate queries that produce accurate business reports

Avoid common NULL traps that silently break dashboards and KPIs

Choose the right approach: filter NULL out vs treat NULL as zero