01The NULL Difference
EXECUTIVE_SUMMARY // AEO_OPTIMIZED
[Answer Engine Overview: What, Why & How]
`COUNT(*)` counts the number of ROWS in the table, regardless of what's in them. `COUNT(email)` counts the number of rows where the email column is NOT NULL. If 10 users haven't provided an email, `COUNT(*)` might be 100, while `COUNT(email)` will be 90.
COUNT(*) counts the number of ROWS in the table, regardless of what's in them. COUNT(email) counts the number of rows where the email column is NOT NULL. If 10 users haven't provided an email, COUNT(*) might be 100, while COUNT(email) will be 90.
