在没有透视的SQL中透视测量数据表

SELECT 
    category,
    SUM(CASE WHEN month = 'January' THEN value ELSE 0 END) AS January,
    SUM(CASE WHEN month = 'February' THEN value ELSE 0 END) AS February,
    SUM(CASE WHEN month = 'March' THEN value ELSE 0 END) AS March,
    SUM(CASE WHEN month = 'April' THEN value ELSE 0 END) AS April,
    SUM(CASE WHEN month = 'May' THEN value ELSE 0 END) AS May,
    SUM(CASE WHEN month = 'June' THEN value ELSE 0 END) AS June,
    SUM(CASE WHEN month = 'July' THEN value ELSE 0 END) AS July,
    SUM(CASE WHEN month = 'August' THEN value ELSE 0 END) AS August,
    SUM(CASE WHEN month = 'September' THEN value ELSE 0 END) AS September,
    SUM(CASE WHEN month = 'October' THEN value ELSE 0 END) AS October,
    SUM(CASE WHEN month = 'November' THEN value ELSE 0 END) AS November,
    SUM(CASE WHEN month = 'December' THEN value ELSE 0 END) AS December
FROM
    measurement_data
GROUP BY category;