COALESCE(value1, value2, ..., valueN)

SELECT 
    customer_id,
    customer_name,
    mobile_phone,
    home_phone,
    work_phone,
    COALESCE(mobile_phone, home_phone, work_phone, 'No phone available') as primary_contact,
    COALESCE(email, backup_email, 'noemail@company.com') as contact_email
FROM

SELECT 
    product_id,
    product_name,
    sale_price,
    regular_price,
    msrp,
    COALESCE(sale_price, regular_price, msrp) as final_price,
    COALESCE(sale_price, regular_price, msrp, 0) as display_price,
    CASE 
        WHEN sale_price IS NOT NULL THEN 'On Sale'
        WHEN regular_price IS NOT NULL THEN 'Regular Price'
        WHEN msrp IS NOT NULL THEN 'MSRP'
        ELSE 'Price Not Set'
    END as price_type
FROM

SELECT 
    order_id,
    customer_id,
    -- Use shipping address if billing address is missing
    COALESCE(billing_address, shipping_address) as invoice_address,
    -- Use estimated date if actual date is missing
    COALESCE(actual_delivery_date, estimated_delivery_date) as delivery_date,
    -- Use default values for missing metrics
    COALESCE(discount_amount, 0) as discount,
    COALESCE(tax_amount, order_total * 0.08) as tax,
    order_total + COALESCE(shipping_cost, 9.99) as total_with_shipping
FROM

SELECT 
    department,
    COUNT(*) as total_employees,
    -- Count employees with bonus (NULL-safe)
    COUNT(bonus_amount) as employees_with_bonus,
    -- Average bonus, treating NULL as 0
    AVG(COALESCE(bonus_amount, 0)) as avg_bonus_including_zeros,
    -- Average bonus, excluding NULLs
    AVG(bonus_amount) as avg_bonus_excluding_nulls,
    -- Total bonus pool
    SUM(COALESCE(bonus_amount, 0)) as total_bonus_pool
FROM employees
GROUP BY

SELECT 
    user_id,
    -- Try profile name, then account name, then email prefix, then 'Anonymous'
    COALESCE(
        profile_display_name,
        account_full_name,
        SPLIT_PART(email, '@', 1),
        'Anonymous User'
    ) as display_name,
    -- Get most recent activity timestamp from multiple sources
    COALESCE(
        last_purchase_date,
        last_login_date,
        account_created_date
    ) as last_activity,
    -- User timezone preference with fallback
    COALESCE(
        user_timezone,
        account_country_timezone,
        'UTC'
    ) as timezone
FROM

SELECT 
    product_id,
    base_price,
    discount_pct,
    tax_pct,
    -- Prevent NULL in calculations
    base_price * (1 - COALESCE(discount_pct, 0)) as price_after_discount,
    base_price * (1 - COALESCE(discount_pct, 0)) * (1 + COALESCE(tax_pct, 0.08)) as final_price
FROM