select query to calculate number of occurrence as well as total cost - mysql

Question

I have one report page which displays summarized data of other report.I have used php and mysqli. Let me explain you in deep.
I have a web application of store, where you can add product details. Using these product details you can generate packaging list report of products. And based on the generated packaging list report I need to generate one other report which contains summarized data of the packaging list.
below are my tables:
product table:
id | name | desc_id | purity | style_no | type | duty
1 | ABC | 1 | 18 | TEST123 | R | 100
2 | XYZ | 2 | 14 | TEST456 | B | 80
3 | DEF | 1 | 14 | TEST122 | R | 80
4 | PQR | 1 | 18 | TEST124 | R | 120
5 | HJK | 3 | 18 | TEST134 | B | 300
Description table:
id | descrip
1 | Gold Diamond Ring
2 | Gold Diamond Pendant
3 | Gold Diamond Earring
packaging_master table
id | name
1 | pkg_1
2 | pkg_2
packging_details table
id | pkg_id | prod_id
1 | 1 | 1
2 | 1 | 2
3 | 1 | 3
4 | 1 | 4
5 | 1 | 5
I have used below query to generate the packaging list report for specific id, which works correctly.
SELECT id, (SELECT descrip FROM description WHERE id = desc_id ) AS descrip,
style_no, type , purity, duty FROM product WHERE id IN ( SELECT prod_id FROM packaging_list_details WHERE pkg_id =1 ) ORDER BY descrip ASC , purity ASC
which displays below result:
id | descrip | style_no | type | purity | duty
1 |Gold Diamond Ring | TEST123 | R | 18 | 100
4 |Gold Diamond Ring | TEST124 | R | 18 | 120
3 |Gold Diamond Ring | TEST122 | R | 14 | 80
2 |Gold Diamond Pendant| TEST456 | B | 14 | 80
5 |Gold Diamond Earring| TEST134 | B | 18 | 300
Now I want summarized data of above result using query.
Like:
id | descrip | purity | qty | duty
1 |Gold Diamond Ring | 18 | 2 | 220
2 |Gold Diamond Ring | 14 | 1 | 80
3 |Gold Diamond Pendant| 14 | 1 | 80
4 |Gold Diamond Earring| 18 | 1 | 300
How can I achieve this?

Answer 1

You need to use the GROUP_BY statement - See MySql docs for more info.
This will translate the query to such
SELECT d.descrip, p.purity, count(p.purity) as qty, sum(p.duty)
FROM product p
INNER JOIN Description d ON p.desc_id = d.id
LEFT OUTER JOIN packaging_details pg on pg.prod_id = p.id
GROUP BY d.descrip, p.purity
ORDER BY d.descrip desc, p.purity desc
You can also use the sub select methodology you were using, but I prefer using joins. INNER JOIN will link both tables so that all their records are returned. OUTER JOIN will return all rows from the tables on the LEFT of the statement and matches them to values from the tables on the RIGHT.
See a full SQL Fiddle sample.
NOTE: I am not sure where you are getting the values for Id in your sample - Are they simply row numbers?

Answer 2

I think you should rewrite your query using JOINs:
SELECT
P.id
,D.descrip
,P.style_no
,P.type
,P.purity
,P.duty
FROM
packaging_list_details PLD
JOIN
product P ON
(P.id = PLD.prod_id)
LEFT JOIN
description D on
(D.desc_id = P.id)
WHERE
(PLID.pkg_id = 1)
That should give you the same result you already have. To get the totals, you can write a new query, similar to the above:
SELECT
P.id
,D.descrip
,P.type
,P.purity
,COUNT(p.id) as total_products
,SUM(P.duty) as total_duty
FROM
packaging_list_details PLD
JOIN
product P ON
(P.id = PLD.prod_id)
LEFT JOIN
description D on
(D.desc_id = P.id)
WHERE
(PLID.pkg_id = 1)
GROUP BY
P.id
,D.descrip
,P.type
,P.purity
The second query gives you the totals you are looking for.