Using CASE for Classification

Syntax

CASE
    WHEN condition1 THEN result1
    WHEN condition2 THEN result2
    ELSE default_result
END

Your Task

Classify leads by data completeness:

• 'Complete' if email AND phone are not null
• 'Partial' if only one of email or phone exists
• 'Minimal' if both email and phone are null

Show: id, first_name, email, phone, data_quality Order by data_quality, then id.