SELECT users.username, SUM(orders.order_total) AS total_order_amount, SUM(orders.order_total) / (SELECT SUM(order_total) FROM orders) * 100 AS order_percent FROM users INNER JOIN orders ON users.user_id = orders.user_id GROUP BY users.user_id ORDER BY order_percent DESC; 如何优化

可以尝试将子查询转化为Join操作，避免多次查询：

SELECT 
    users.username, 
    SUM(orders.order_total) AS total_order_amount, 
    SUM(orders.order_total) / total_sum_order_total.sum_order_total * 100 AS order_percent 
FROM 
    users 
    INNER JOIN orders ON users.user_id = orders.user_id 
    CROSS JOIN (SELECT SUM(order_total) AS sum_order_total FROM orders) AS total_sum_order_total
GROUP BY 
    users.user_id 
ORDER BY 
    order_percent DESC;

同时，可以根据数据量和查询频率，考虑在相关表上创建索引，以加快查询速度。

相关问题

SUM(orders.order_total) / (SELECT SUM(order_total) FROM orders) * 100 AS order_percent

这是一条SQL语句，用于计算某个订单的总金额在所有订单总金额中所占的百分比。其中，SUM(orders.order_total)用于计算某个订单的总金额，(SELECT SUM(order_total) FROM orders)用于计算所有订单的总金额，最后将两者相除并乘以100得到百分比。结果将被命名为order_percent。

SELECT orders.id,orders.user_id,orders.cityarea_id,orders.batchcode,orders.status, orders.pay_status,orders.real_pay,orders.total,orders.money,orders.pay_type, orders.premium,orders.createtime,orders.paytime,orders.confirmtime, orders.is_evaluate,orders.pay_method,orders.exp_user_id, orders.return_score, orders.is_change,orders.reward_money,orders.isvalid,orders.after_sale_status,orders.remark, orders.use_coupon_detail,orders.block_chain_price, users.name,users.weixin_name,users.weixin_fromuser, users.phone,wcoe.diy_area_name ,writes.ActivityStatus,writes.NewMoney,records.Commission,records.ReturnRadio from wsy_o2o.weixin_cityarea_orders orders left join wsy_o2o.weixin_cityarea_supply supply on orders.cityarea_id = supply.id left join wsy_o2o.weixin_cityarea_payonline_orders wcco on orders.batchcode=wcco.batchcode left join wsy_user.weixin_users users on users.id = orders.user_id LEFT JOIN wsy_o2o.weixin_cityarea_orders_extend wcoe ON orders.batchcode = wcoe.batchcode LEFT JOIN wsy_dream.ShopWrite writes on orders.batchcode = writes.Batchcode LEFT JOIN wsy_o2o.weixin_cityarea_supply_commissons_record records ON orders.cityarea_id = records.SupplyId and records.CreateTime < orders.createtime ORDER BY records.CreateTime DESC LIMIT 1 WHERE orders.types=3 and orders.customer_id = 41 AND orders.isvalid=true GROUP BY orders.batchcode ORDER BY orders.id DESC limit 0,20; 以上代码报错，怎么解决

根据您提供的查询代码，有几个问题需要解决：

1. `LIMIT` 和 `ORDER BY` 语句的顺序错误。在 `ORDER BY` 之前应该是 `WHERE` 语句，然后是 `GROUP BY`，最后是 `ORDER BY` 和 `LIMIT`。请将这两个语句调整到正确的位置。

2. `LEFT JOIN` 和 `JOIN` 语句之间缺少逗号。请在第一个 `LEFT JOIN` 语句和第二个 `LEFT JOIN` 语句之间添加逗号。

修改后的代码如下：

SELECT orders.id, orders.user_id, orders.cityarea_id, orders.batchcode, orders.status, 
orders.pay_status, orders.real_pay, orders.total, orders.money, orders.pay_type, 
orders.premium, orders.createtime, orders.paytime, orders.confirmtime, 
orders.is_evaluate, orders.pay_method, orders.exp_user_id, orders.return_score,
orders.is_change, orders.reward_money, orders.isvalid, orders.after_sale_status, orders.remark,
orders.use_coupon_detail, orders.block_chain_price, users.name, users.weixin_name, users.weixin_fromuser,
users.phone, wcoe.diy_area_name , writes.ActivityStatus, writes.NewMoney, records.Commission, records.ReturnRadio
FROM wsy_o2o.weixin_cityarea_orders orders 
LEFT JOIN wsy_o2o.weixin_cityarea_supply supply ON orders.cityarea_id = supply.id 
LEFT JOIN wsy_o2o.weixin_cityarea_payonline_orders wcco ON orders.batchcode = wcco.batchcode 
LEFT JOIN wsy_user.weixin_users users ON users.id = orders.user_id 
LEFT JOIN wsy_o2o.weixin_cityarea_orders_extend wcoe ON orders.batchcode = wcoe.batchcode
LEFT JOIN wsy_dream.ShopWrite writes ON orders.batchcode = writes.Batchcode 
LEFT JOIN wsy_o2o.weixin_cityarea_supply_commissons_record records ON orders.cityarea_id = records.SupplyId AND records.CreateTime < orders.createtime 
WHERE orders.types = 3 AND orders.customer_id = 41 AND orders.isvalid = true 
GROUP BY orders.batchcode 
ORDER BY records.CreateTime DESC 
LIMIT 1 OFFSET 0;

请注意，上述修改的代码仅修复了语法错误。如果仍然存在问题，可能需要进一步检查表和列名的正确性以及其他约束条件。