mysql 多个分组查询

SELECT 
    DATE_FORMAT(date, '%Y-%m') AS month,
    product,
    region,
    SUM(sales_amount) AS total_sales
FROM 
    sales
GROUP BY 
    month, product, region;

-- 错误示例
SELECT 
    product,
    region,
    DATE_FORMAT(date, '%Y-%m') AS month,
    SUM(sales_amount) AS total_sales
FROM 
    sales
GROUP BY 
    product, region;

-- 正确示例
SELECT 
    DATE_FORMAT(date, '%Y-%m') AS month,
    product,
    region,
    SUM(sales_amount) AS total_sales
FROM 
    sales
GROUP BY 
    month, product, region;

-- 创建索引
CREATE INDEX idx_date_product_region ON sales(date, product, region);

-- 使用EXPLAIN分析查询计划
EXPLAIN SELECT 
    DATE_FORMAT(date, '%Y-%m') AS month,
    product,
    region,
    SUM(sales_amount) AS total_sales
FROM 
    sales
GROUP BY 
    month, product, region;