在mysql中无法正确获取订单总和和订单值

Question

我有4张桌子.

table_orders

order_id
customer_id
order_datetime
order_payment_type
order_delivery_date
delivery_time_slot  

table_order_details

order_id
product_id
varient_id
quantity
product_mrp
product_sell_price
product_name

table_order_status

order_id
status_id
status_datetime

table_order_status_values

value_id
value_desc  

我想获得订单ID,订单金额,订单日期,订单数量,订单时间,value_desc.

我正在运行此查询.

SELECT oo.order_id, oo.amount, oo.date, oo.quantity, oo.time, value_desc
FROM 
(
     SELECT s.order_id,  SUM(OD.product_sell_price * OD.quantity) as amount, 
       DATE_FORMAT(o.order_datetime, '%d/%m/%Y') as date, SUM(OD.quantity) 
       as quantity, TIME(o.order_datetime) as time, MAX( status_id ) as laststatus
     FROM table_orders o
     INNER JOIN table_order_details AS OD ON o.order_id = OD.order_id
     INNER JOIN table_order_status s ON s.order_id = o.order_id
     GROUP BY o.order_id
)oo

INNER JOIN table_order_status_values ON value_id = laststatus

order by order_id DESC

样本数据:

Table_orders

1 1 2015:12:12:19:42:47 1 2015:12:14 1

table_order_details

1 12 3 1 21.00 20.00 abcd
1 13 2 2 100.00 90.00 efgh

table_order_status

1 1 2015:12:12:19:42:47
1 2 2015:12:12:20:42:47

table_order_status_values

1 NEW ORDER
2 CONFIRM
3 Delivered

用上面的查询输出是:

1 400.00 12:12:2015 6 19:42:47 CONFIRM

但预期产量是:

1 200.00 12:12:2015 3 19:42:47 CONFIRM 

我根据给定订单的状态数量获得订单金额和订单数量值两次(或三次).

怎么纠正这个？任何帮助将受到高度赞赏.

Answer 1

您应该首先将子选择的重点放在获取除状态之外的所有订单信息上，然后加入状态信息。

这可能看起来像这样：

SELECT
    order_with_status.order_id AS order_id,
    order_with_status.amount AS amount,
    order_with_status.`date` AS `date`,
    order_with_status.quantity AS quantity,
    order_with_status.`time` AS `time`,
    tosv.value_description AS current_status       
FROM (
    /* Add maximum order status value to result set */
    SELECT
        order.order_id AS order_id,
        order.amount AS amount,
        order.`date` AS `date`,
        order.quantity AS quantity,
        order.`time` AS `time`,
        MAX(tos.status) AS current_status_id
    FROM (
        /* Get rolled-up order information as start to result set */
        SELECT
            o.order_id AS order_id,
            SUM(od.product_sell_price * od.quantity) AS amount,
            DATE_FORMAT(o.order_datetime, '%d/%m/%Y') AS `date`,
            SUM(od.quantity) AS `quantity`,
            TIME(o.order_datetime) AS `time`
        FROM table_orders AS o
        INNER JOIN table_order_details AS od
            ON o.order_id = od.order_id
        GROUP BY o.order_id
    ) as order
    INNER JOIN table_order_status AS tos
        ON order.order_id = tos.order_id
) as order_with_status
INNER JOIN table_order_status_values AS tosv
    ON order_with_status.current_status_id = tosv.value_id

ORDER BY order_with_status.order_id DESC

请注意，您的架构本身使得这是一个非常复杂的查询，如果您需要在系统中定期执行此查询，则可能无法很好地执行此查询。如果您进行简单的更改以将订单状态 id 字段移至订单表中，则可以大大简化此操作（将 table_order_status 表降级为仅作为此类查询中根本不使用的状态更改的审核历史记录）。这在逻辑上是有意义的，因为当尝试简单地获取当前订单数据时，似乎不需要处理订单的更改历史记录。

在这种情况下，查询可以像这样简单

SELECT
    o.order_id AS order_id,
    tosv.value_description AS current_status,
    SUM(od.product_sell_price * od.quantity) AS amount,
    DATE_FORMAT(o.order_datetime, '%d/%m/%Y') AS `date`,
    SUM(od.quantity) AS quantity,
    TIME(o.order_datetime) AS `time`
FROM table_orders AS o
INNER JOIN table_order_status_values AS tosv
    ON o.order_status_id = tosv.value_id
INNER JOIN table_order_details AS od
    ON o.order_id = od.order_id
GROUP BY o.order_id
ORDER BY o.order_id DESC

如果您想将状态描述而不是 ID 放入订单表中，则可以进一步简化这一点（这将消除额外的表连接来获取描述）。

现在，这种明显的反规范化对您的应用程序是否有意义在很大程度上取决于应用程序的用例。例如，如果您访问审计数据的次数不多，或者只需要在单个订单的上下文中显示此数据，那么这可能是有意义的。