Query to get data from four tables - mysql

Question

i have following scheme,
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 |
+-------------------+--------------------------+-------------------+
stock
+----------+-------------------+------------+----------+------------------+---------------+
| 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 |
+----------+-------------------+------------+----------+------------------+---------------+
i have write this query but it returns duplicate results
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
;
The results
+---------------------+----------------------+------------+-----------+------------------+-------------------+---------------------+---------------------------------------+
| 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 |
+---------------------+----------------------+------------+-----------+------------------+-------------------+---------------------+---------------------------------------+
relationship is one to many from top to bottom.
What I wanted to get is the each purchase_order , his ordered quantity of each item, and total recieved quantity, and quantity in stock where project_id = 1 from stock.
i am expecting something like this,
+-------------------+---------+------------------+---------------+----------+
| purchase_order_id | item_id | ordered_quantity | totalReceived | quantity |
+-------------------+---------+------------------+---------------+----------+
| 54 | 279 | 500 | 314 | 192 |
| 54 | 286 | 700 | 300 | 170 |
| 56 | 279 | 43 | 34 | 12 |
+-------------------+---------+------------------+---------------+----------+

Answer 1

EDIT
Thank you for clearing up the mistake in my first part. I realize now that we cannot do all calculations in a single query (because we group on different columns in various parts) so I started by writing individual subqueries and joining them together. The steps went something like this:
Get the sum of received total received quantity for each
purchase_order_detail_id from the delivery_order table.
Join that subquery with the delivery_order table itself to get the totalReceived for the various delivery_order_id values.
Join that result set with the purchase_order_detail table to get the purchase_order_id, item_id, and ordered_quantity for each delivery_order_id.
We now have a result set including the delivery_order_id, purchase_order_id, item_id, ordered_quantity, and total received. The last two things are:
Get the SUM() of quantity for each delivery_order_id from the stock table.
Join that with our above result set on the condition that order_id matches (so we will only get one row) and that project_id is 1 (so we only get the necessary delivery_order_id values). I put that condition in the WHERE clause of the sum subquery.
Here is your final query:
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;
Here is the SQL Fiddle. It shows all of the intermediate steps too, if you'd like to see how the results came together individually.

Answer 2

Try modifying your query to use DISTINCT and OUTER JOINs instead of cartesian ("comma") joins.
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
;