mysql的switch case

SELECT 
    product_id,
    CASE 
        WHEN price < 10 THEN 'Low'
        WHEN price BETWEEN 10 AND 50 THEN 'Medium'
        ELSE 'High'
    END AS price_category
FROM products;

SELECT 
    product_id,
    CASE 
        WHEN price < 10 THEN 'Low'
        WHEN price BETWEEN 10 AND 50 THEN 'Medium'
        WHEN price > 50 THEN 'High'
        ELSE 'Unknown'
    END AS price_category
FROM products;

SELECT 
    product_id,
    SWITCH(price_category) (
        CASE 'Low' THEN 'Discounted'
        CASE 'Medium' THEN 'Regular'
        CASE 'High' THEN 'Premium'
        DEFAULT 'Unknown'
    ) AS pricing_tier
FROM (
    SELECT 
        product_id,
        CASE 
            WHEN price < 10 THEN 'Low'
            WHEN price BETWEEN 10 AND 50 THEN 'Medium'
            ELSE 'High'
        END AS price_category
    FROM products
) AS subquery;