MySQL GROUP BY with subquery（ies）

Question

我试图计算日期范围内的订单数量，按日期分组，但也计算在同一日期发生的其他一些记录。

我有一个查询看起来是这样的：

SELECT 
order_date, 
DATE_FORMAT(order_date,'%W') AS day, 
DATE_FORMAT(order_date,'%d-%m-%Y') AS orderdate, 
COUNT(orderID) As orders, 
a.something AS something 
b.something AS something_else, 
a.something + b.something AS total_somethings 
FROM orders, 
(SELECT COUNT(*) AS something FROM other_table) AS a, 
(SELECT COUNT(*) AS something FROM another_table) AS b, 
GROUP BY order_date 
HAVING order_date >= '2014-01-01' AND order_date <= '2014-01-31' 
ORDER BY order_date ASC 

它的工作原理确定，但很明显，子查询计算每一行。表'other_table'和'another_table'都有日期字段，我想用它来限制每行的结果。

我试图改变子查询是这样的：

(SELECT COUNT(*) AS something FROM other_table WHERE date_field = order_date) AS a, 

，但它仍然是计算每一行。

任何意见赞赏。

感谢

Answer 1

在下面的查询，我在other_table和another_table表分组的date_field。然后，我使用date_field与orders表加入。以下查询是否适合您？

SELECT 
order_date, 
DATE_FORMAT(order_date,'%W') AS day, 
DATE_FORMAT(order_date,'%d-%m-%Y') AS orderdate, 
COUNT(orderID) As orders, 
a.something AS something 
b.something AS something_else, 
a.something + b.something AS total_somethings 
FROM orders, 
(SELECT date_field, COUNT(*) AS something FROM other_table GROUP BY date_field) AS a, 
(SELECT date_field, COUNT(*) AS something FROM another_table GROUP BY date_field) AS b 
WHERE order_date >= '2014-01-01' AND order_date <= '2014-01-31' 
AND order_date = a.date_field AND order_date = b.date_field 
GROUP BY order_date 
ORDER BY order_date ASC;