Conditional Functions

SELECT COALESCE(preferred_email, backup_email, 'unknown') AS email
FROM company_data."123"

SELECT NULLIF(status, 'unknown') AS clean_status
FROM company_data."123"

SELECT IF(score > 90, 'A', 'B') AS grade
FROM company_data."123"

SELECT
  CASE
    WHEN score >= 90 THEN 'A'
    WHEN score >= 80 THEN 'B'
    WHEN score >= 70 THEN 'C'
    ELSE 'F'
  END AS grade
FROM company_data."123"