我有以下方案， 的 PURCHASE_ORDER
+-------------------+----------------------+
| purchase_order_id | purchase_order |
+-------------------+----------------------+
| 54 | Purchase Order 12345 |
| 56 | po-laptop-hp-3 |
| 57 | po-laptop-hp-1 |
+-------------------+----------------------+
purchase_order_detail
+--------------------------+-------------------+---------+------------------+
| purchase_order_detail_id | purchase_order_id | item_id | ordered_quantity |
+--------------------------+-------------------+---------+------------------+
| 61 | 54 | 279 | 500 |
| 62 | 54 | 286 | 700 |
| 63 | 56 | 279 | 43 |
| 64 | 57 | 279 | 43 |
| 65 | 57 | 286 | 43 |
| 66 | 57 | 287 | 43 |
+--------------------------+-------------------+---------+------------------+
delivery_order
+-------------------+--------------------------+-------------------+
| delivery_order_id | purchase_order_detail_id | recieved_quantity |
+-------------------+--------------------------+-------------------+
| 62 | 61 | 250 |
| 63 | 62 | 300 |
| 64 | 63 | 34 |
| 65 | 64 | 34 |
| 66 | 65 | 34 |
| 67 | 66 | 34 |
| 68 | 61 | 34 |
| 69 | 61 | 34 |
+-------------------+--------------------------+-------------------+
股票</强>
+----------+-------------------+------------+----------+------------------+---------------+
| stock_id | delivery_order_id | project_id | quantity | initial_quantity | stock_type_id |
+----------+-------------------+------------+----------+------------------+---------------+
| 12 | 62 | 1 | 60 | 60 | 1 |
| 13 | 63 | 1 | 120 | 120 | 1 |
| 14 | 63 | 1 | 50 | 50 | 1 |
| 15 | 64 | 1 | 12 | 12 | 1 |
| 16 | 62 | 1 | 120 | 120 | 1 |
| 17 | 62 | 1 | 12 | 12 | 1 |
+----------+-------------------+------------+----------+------------------+---------------+
我已经写了这个查询，但它返回了重复的结果
SELECT po.created_on
, po.purchase_order
, i.item_name
, u.unit_name
, pod.ordered_quantity
, do.recieved_quantity
, do.recieved_on
, po.remarks
FROM purchase_order po
, purchase_order_detail pod
, delivery_order do
, stock s
, item i
, unit u
WHERE u.unit_id = i.unit_id
AND i.item_id = pod.item_id
AND po.purchase_order_id = pod.purchase_order_id
AND pod.purchase_order_detail_id = do.purchase_order_detail_id
AND do.delivery_order_id = s.delivery_order_id
AND s.project_id = 1
ORDER BY po.purchase_order_id
, pod.item_id
;
结果
+---------------------+----------------------+------------+-----------+------------------+-------------------+---------------------+---------------------------------------+
| created_on | purchase_order | item_name | unit_name | ordered_quantity | recieved_quantity | recieved_on | remarks |
+---------------------+----------------------+------------+-----------+------------------+-------------------+---------------------+---------------------------------------+
| 2015-02-24 22:48:15 | Purchase Order 12345 | HP Laptops | Unit | 500 | 250 | 2015-02-21 00:00:00 | Adding first Purchase Order as a Test |
| 2015-02-24 22:48:15 | Purchase Order 12345 | HP Laptops | Unit | 500 | 250 | 2015-02-21 00:00:00 | Adding first Purchase Order as a Test |
| 2015-02-24 22:48:15 | Purchase Order 12345 | Lenovo | Unit | 700 | 300 | 2015-02-21 00:00:00 | Adding first Purchase Order as a Test |
| 2015-02-24 22:48:15 | Purchase Order 12345 | Lenovo | Unit | 700 | 300 | 2015-02-21 00:00:00 | Adding first Purchase Order as a Test |
| 2015-02-24 22:55:40 | po-laptop-hp-3 | HP Laptops | Unit | 43 | 34 | 2015-02-21 00:00:00 | dfgsdfgsd |
+---------------------+----------------------+------------+-----------+------------------+-------------------+---------------------+---------------------------------------+
关系从上到下是一对多。 我想得到的是每个purchase_order，每个项目的订购数量，总收货数量，以及库存中project_id = 1的库存数量。
我期待这样的事情，
+-------------------+---------+------------------+---------------+----------+
| purchase_order_id | item_id | ordered_quantity | totalReceived | quantity |
+-------------------+---------+------------------+---------------+----------+
| 54 | 279 | 500 | 314 | 192 |
| 54 | 286 | 700 | 300 | 170 |
| 56 | 279 | 43 | 34 | 12 |
+-------------------+---------+------------------+---------------+----------+
答案 0 :(得分：2)
修改
感谢您在我的第一部分中清除错误。我现在意识到我们不能在一个查询中进行所有计算（因为我们将各个部分放在不同的列上）所以我开始编写单个子查询并将它们连接在一起。步骤是这样的：
我们现在有一个结果集，包括delivery_order_id，purchase_order_id，item_id，ordered_quantity和收到的总数。最后两件事是：
WHERE子句中。这是您的最终查询：
SELECT tmp1.purchase_order_id, tmp1.item_id, tmp1.ordered_quantity, tmp1.totalReceived, tmp2.quantity
FROM(
SELECT tmp.delivery_order_id, pod.purchase_order_id, pod.item_id, pod.ordered_quantity, tmp.totalReceived
FROM purchase_order_detail pod
JOIN(
SELECT do.delivery_order_id, tmp.purchase_order_detail_id, tmp.totalReceived
FROM delivery_order do
JOIN(
SELECT do.purchase_order_detail_id, SUM(do.received_quantity) AS totalReceived
FROM delivery_order do
GROUP BY do.purchase_order_detail_id) tmp ON tmp.purchase_order_detail_id = do.purchase_order_detail_id)
tmp ON tmp.purchase_order_detail_id = pod.purchase_order_detail_id) tmp1
JOIN(
SELECT s.delivery_order_id, SUM(quantity) AS quantity
FROM stock s
WHERE s.project_id = 1
GROUP BY s.delivery_order_id) tmp2 ON tmp2.delivery_order_id = tmp1.delivery_order_id;
这是SQL Fiddle。它还显示了所有中间步骤，如果您想看看结果如何单独组合在一起。
答案 1 :(得分：0)
尝试修改您的查询以使用DISTINCT和OUTER JOIN而不是笛卡尔（＆＃34;逗号＆＃34;）连接。
SELECT DISTINCT po.created_on
, po.purchase_order
, i.item_name
, u.unit_name
, pod.ordered_quantity
, do.recieved_quantity
, do.recieved_on
, po.remarks
FROM purchase_order po
LEFT JOIN purchase_order_detail pod USING (purchase_order_id)
LEFT JOIN delivery_order do USING (purchase_order_detail_id)
LEFT JOIN stock s USING (delivery_order_id)
LEFT JOIN item i USING (item_id)
LEFT JOIN unit u USING (unit_id)
ORDER BY po.purchase_order_id
, pod.item_id
;