Rails 3 Sum Product of two fields - sql

I need to calculate the sum of the product of two fields in my Rails 3 app (i.e. the equivalent to Excel's sumproduct function). Is there a method in Rails that will help with this and if not, then what would be the rails code using custom sql?
For example, a Hotel has many Rooms. A Room has attributes of sqft (square feet), quantity (of that size) and hotel_id. I would like to calculate the total sqft of all the Rooms in a given Hotel. In SQL, for a Hotel.id = 8, I believe the following statement will work:
select sum(rooms.sqft * rooms.quantity) as SumSqft from rooms inner join hotels on rooms.hotel_id = hotels.id where hotels.id = 8;

Yep :
Room.where(hotel_id: 8).sum("sqft * quantity")

def calculate
#hotel=Hotel.find(params[:id]
#rooms=Room.all.where(:hotel_id=>#hotel.id)
sum=0
#rooms.each do |room|
sum=sum+room.sqft*room.quantity
end
return sum
end

Related

Django ORM equivalent of SQL Sum

I have a django model as follows:
class Order(models.Model):
cash=models.DecimalField(max_digits=11,decimal_places=2,default=0)
balance=models.DecimalField(max_digits=11,decimal_places=2,default=0)
current_ac=models.DecimalField(max_digits=11,decimal_places=2,default=0)
added_by = models.ForeignKey(User)
There can be multiple Orders and multiple users can create orders.
How can I get the sum of all orders for each columns for a particular user using Django queries, an SQL equivalent would be something like
Select sum(cash), sum (balance), sum(current_ac) from Orders where added_by = 1
You can get your expected result from the code below
from django.db.models import Sum
result = Order.objects.filter(added_by_id=1).aggregate(total_cash=Sum('cash'), total_balance =Sum('balance'), total_current_ac=Sum('current_ac'))
and it will give you a dictionary like this:
{'total_cash': Decimal('110.00'), 'total_balance': Decimal('110.00'), 'total_current_ac': Decimal('110.00')}

multiplie outputs with different wheres

What do I have to change to get different results from different names.The table should give me the debts of each of them, this is calculated by the amount and the price of the drink. Now it should show all the names with the corresponding invoice that happens after the select
%sql select name, sum(getraenk.preis*schulden.menge) schulden from schulden \
join person on (fk_person = person.id)\
join getraenk on (fk_getraenk = getraenk.id)\
where name like ("dani")
Edit: it should spend all the names with their debts, that is:
dani = 8.5
michael = 12.5
...
Just in case your problem is very simple, you should be able to see all names and values with an SQL that looks like this:
select name, getraenk.preis*schulden.menge schulden
from schulden
join person on (fk_person = person.id)
join getraenk on (fk_getraenk = getraenk.id)
Note that I removed the where clause... this was the part that limited it to one name.
You also don't need the sum clause here unless you are doing a group by
Have you considered simply using GROUP BY name at the end of this query?
https://www.w3schools.com/sql/sql_groupby.asp
This will give you the sum of total debt for all names in your table which sounds like the result you are looking for.
You're missing
GROUP BY name
in the query.

Access SQL query - Percentage of Total calculation

In Access SQL, I am attempting what should seem like a simple task in attaining a percentage of total. There are 3 item stores (Sears, kmart & Mktpl) of which in any given week, I wish to calculate their respective percent of total based on balance of sales (all can be obtained using one table - tbl_BUChannelReporting).
For example week 5 dummy numbers - Sears 7000, kmart 2500, mktpl 2000
the following ratios would be returned: sears 61%, kmart 22%, mktpl 17%
I was originally trying to create a sub query and wasn't getting anywhere so I am essentially trying to sum sales on one of the item stores in week 5 divided by the sum of all 3 item store sales in week 5. The following is my query, which is giving me "cannot have aggregate function in expression" error:
SELECT FY, FW, Rept_Chnl, BU_NM, Order_Store, Item_Store, CDBL(
SUM(IIF([item_store]="sears", revenue, IIF([item_store]="kmart", revenue, IIF([item_store]="mktpl", revenue,0)))) /
(SUM(IIF([item_store]="sears",revenue,0)+SUM(IIF([item_store]="kmart",revenue,0)+SUM(IIF([item_store]="mktpl",revenue,0))))))
AS Ratios
FROM tbl_BUChannelReporting
WHERE FY = "2017"
AND FW = 5
GROUP BY FY, FW, Rept_Chnl, BU_NM, Order_Store, item_store
Thanks all in advance for taking the time. This is my 1st post here and I don't consider myself anything but a newbie anxious to learn from the best and see how this turns out.
Take care!
-D
Consider using two derived tables or saved aggregate queries: one that groups on Item_Store and the other that does not include Item_Store in order to sum the total stores' revenue. All other groupings (FY, FW, Rept_Chnl, BU_NM, Order_Store) remain in both and used to join the two. Then in outer query, calculate percentage ratio.
SELECT i.*, CDbl(i.Store_Revenue / a.Store_Revenue) As Ratios
FROM
(SELECT t.FY, t.FW, t.Rept_Chnl, t.BU_NM, t.Order_Store, t.Item_Store,
SUM(t.Revenue) As Store_Revenue
FROM tbl_BUChannelReporting t
WHERE t.FY = '2017' AND t.FW = 5
GROUP BY t.FY, t.FW, t.Rept_Chnl, t.BU_NM, t.Order_Store, t.Item_Store) As i
INNER JOIN
(SELECT t.FY, t.FW, t.Rept_Chnl, t.BU_NM, t.Order_Store
SUM(t.Revenue) As Store_Revenue
FROM tbl_BUChannelReporting t
WHERE t.FY = '2017' AND t.FW = 5
GROUP BY t.FY, t.FW, t.Rept_Chnl, t.BU_NM, t.Order_Store) As a
ON i.FY = a.FY AND i.FW = a.FW AND i.Rept_Chnl = a.Rept_Chnl
AND i.BU_NM = a.BU_NM AND i.Order_Store = a.Order_Store
Or save each above SELECT statement as its own query and reference both below:
SELECT i.*, (i.Store_Revenue / a.Store_Revenue) As Ratios
FROM
Indiv_Item_StoreAggQ As i
INNER JOIN
All_Item_StoreAggQ As a
ON i.FY = a.FY AND i.FW = a.FW AND i.Rept_Chnl = a.Rept_Chnl
AND i.BU_NM = a.BU_NM AND i.Order_Store = a.Order_Store

How to using subquery values in arithmetic operations

My manager wants to see what is total values of our suppliers shipments, and what is the total values of their invoices recorded. So he can see the differencies and want from suppliers to unsended invoices.
Here is my code.
It is working on accounting table and shipment detail table.
fis_meblag0 is always little from zero because it is 320 account so I mutiply it -1 for get real value.
sth_tutar is value of shipment, sth_vergi is VAT and so the sum of them is equal to sum of total with VAT.
Now the hard part.
Manager wants to diference between them in a other column and also sort the valuez z to a.
I know I can reuse same subselect for the getting totals but I want to know that can I achieve this without using the same subquery again.
I mean in first subselect I have the total, in last column I only need just the total, can I use total without compute it again?
Regards
select
ch.cari_kod as Carikod,
ch.cari_unvan1 as Unvani,
(select (sum(mf.fis_meblag0) * -1)
from dbo.MUHASEBE_FISLERI mf
where (mf.fis_tarih > '20141231' and mf.fis_tarih < '20150201')
and mf.fis_hesap_kod = ch.cari_kod
and mf.fis_meblag0 < 0) as mtoplam,
(Select sum (sth.sth_tutar + sth.sth_vergi)
from dbo.STOK_HAREKETLERI sth
where (sth.sth_tarih > '20141231' and sth.sth_tarih < '20150201')
and sth.sth_cari_kodu = ch.cari_kod
and sth.sth_normal_iade = 0
and sth.sth_tip = 0) as stoplam
from
dbo.CARI_HESAPLAR ch
where
ch.cari_kod like '320%'
try this query:
select Carikod, Unvani, mtoplam, stoplam, mtoplam - stoplam as Grand_total
from
(
-- your full query here
) T

SUM(a*b) not working

I have a PHP page running in postgres. I have 3 tables - workorders, wo_parts and part2vendor. I am trying to multiply 2 table column row datas together, ie wo_parts has a field called qty and part2vendor has a field called cost. These 2 are joined by wo_parts.pn and part2vendor.pn. I have created a query like this:
$scoreCostQuery = "SELECT SUM(part2vendor.cost*wo_parts.qty) as total_score
FROM part2vendor
INNER JOIN wo_parts
ON (wo_parts.pn=part2vendor.pn)
WHERE workorder=$workorder";
But if I add the costs of the parts multiplied by the qauntities supplied, it adds to a different number than what the script is doing. Help....I am new to this but if someone can show me in SQL I can modify it for postgres. Thanks
Without seeing example data, there's no way for us to know why you're query totals are coming out differently that when you do the math by hand. It could be a bad join, so you are getting more/less records than you expected. It's also possible that your calculations are off. Pick an example with the smallest number of associated records & compare.
My suggestion is to add a GROUP BY to the query:
SELECT SUM(p.cost * wp.qty) as total_score
FROM part2vendor p
JOIN wo_parts wp ON wp.pn = p.pn
WHERE workorder = $workorder
GROUP BY workorder
FYI: MySQL was designed to allow flexibility in the GROUP BY, while no other db I've used does - it's a source of numerous questions on SO "why does this work in MySQL when it doesn't work on db x...".
To Check that your Quantities are correct:
SELECT wp.qty,
p.cost
FROM WO_PARTS wp
JOIN PART2VENDOR p ON p.pn = wp.pn
WHERE p.workorder = $workorder
Check that the numbers are correct for a given order.
You could try a sub-query instead.
(Note, I don't have a Postgres installation to test this on so consider this more like pseudo code than a working example... It does work in MySQL tho)
SELECT
SUM(p.`score`) AS 'total_score'
FROM part2vendor AS p2v
INNER JOIN (
SELECT pn, cost * qty AS `score`
FROM wo_parts
) AS p
ON p.pn = p2v.pn
WHERE p2n.workorder=$workorder"
In the question, you say the cost column is in part2vendor, but in the query you reference wo_parts.cost. If the wo_parts table has its own cost column, that's the source of the problem.