I couldn't come up with an appropriate title, excuse me for which.
The situation is the following:
I've got two tables: montages and orders, where Montage belongs to Order.
My goal is to build a single mysql query which to return a single float value to represent a sum of values for multiple montages. For each montage in the query I need to divide the budget of its order by the number of montages which belong to the same order. The result of this division should be an attribute of ecah montage. Finally, I want to sum those attributes and retrieve a single value.
I've tried a lot of variation of something like the following, but none seemed to be written in correct syntax, so I kept getting errors:
$sum = App\Montage::where(/*this doesn't matter*/)
->join('orders', 'montages.order_id', '=', 'orders.id') //join the orders table
->select('montages.*, orders.budget') //include the budget column
->selectRaw('count(* where order_id = order_id) as all') //count all the montages of the same order and assing that count to the current montage
->selectRaw('(orders.budget / all) as daily_payment') //divide the budget of the order by the count; store the result as `daily_payment`
->sum('daily_payment') //sum the daily payments
I'm really lost with the proper syntax and can't figure it out. I'd estimate that to be a rather trivial sql task for people who know their stuff, but unfortunately I don't seem to be one of them... Any help is greatly appreciated!
Related
I want to add the price field from the enginestable with the buying_price field from the vehicles table where we have several purchases of vehicles and several engines and I want to sum the final cost for each purchases
I have the following tables
I want to add the price field from the enginestable with the buying_price field from the vehicles table where we have several purchases of vehicles and several engines and I want to sum the final cost for each purchases
I wrote the following command, but I get an error:
$purchase=DB::table('purchases')
->leftjoin('vehicles', 'vehicles.purchase_id', '=','purchases.id')
->leftjoin('engines', 'engines.purchase_id','=','purchases.id')
->leftjoin('suppliers', 'suppliers.id', '=', 'purchases.supplier_id')
->select('purchases.id','suppliers.name','purchases.purchase_date','vehicles.buying_price','engines.price')->get()
->collect('vehicles.buying_price','engines.price')->sum();
return $purchase
this is the the error:
In short, how do I add two values from two different tables and show them in another table?
you can call back of sum instead of collect.
For example Try this:-
$purchase=DB::table('purchases')
->leftjoin('vehicles', 'vehicles.purchase_id', '=','purchases.id')
->leftjoin('engines', 'engines.purchase_id','=','purchases.id')
->leftjoin('suppliers', 'suppliers.id', '=', 'purchases.supplier_id')
->select('purchases.id','suppliers.name','purchases.purchase_date','vehicles.buying_price','engines.price')->get()
->sum(function($data){
return $data->buying_price + $data->price;
});
I've been trying to do a report about the quantity of breakdonws of products in our company. The problem is that the QUERY function is operating as normal, but the sorting order is well - a bit strange.
The data I'm trying to sort are as follows (quantities are blacked out since I cannot share those informations):
Raw data
First column - name of the product, second, it's EAN code, third, breakdown rate for last year, last column - average breakdown rate. "b/d" means "brak danych" or no data.
What I want to achieve is to get the end table with values sorted by average breakdown rate.
My query is as follows:
=query(Robocze!A2:D;"select A where A is not null and NOT D contains 'b/d' order by D desc")
Final result
As You can see, we have descending order, but there are strange artifacts - like the 33.33% after 4,00% and before 3,92%.
Why is that!?
try:
=INDEX(LAMBDA(x; SORT(x; INDEX(x;; 4)*1; 0))
(QUERY(Robocze!A2:D; "where A is not null and NOT D contains 'b/d'"; 0));; 4)
I am having trouble to understand why a for loop construction does not work. I am not really used to for loops so I apologize if I am missing something basic. Anyhow, I appreciate any piece of advice you might have.
I am using a party level dataset from the parlgov project. I am trying to create a variable which captures how many times a party has been in government before the current observation. Time is important, the counter should be zero if a party has not been in government before, even if after the observation period it entered government multiple times. Parties are nested in countries and in cabinet dates.
The code is as follows:
use "http://eborbath.github.io/stackoverflow/loop.dta", clear //to get the data
if this does not work, I also uploaded in a csv format, try:
import delimited "http://eborbath.github.io/stackoverflow/loop.csv", bindquote(strict) encoding(UTF-8) clear
The loop should go through each country-specific cabinet date, identify the previous observation and check if the party has already been in government. This is how far I have got:
gen date2=cab_date
gen gov_counter=0
levelsof country, local(countries) // to get to the unique values in countries
foreach c of local countries{
preserve // I think I need this to "re-map" the unique cabinet dates in each country
keep if country==`c'
levelsof cab_date, local(dates) // to get to the unique cabinet dates in individual countries
restore
foreach i of local dates {
egen min_date=min(date2) // this is to identify the previous cabinet date
sort country party_id date2
bysort country party_id: replace gov_counter=gov_counter+1 if date2==min_date & cabinet_party[_n-1]==1 // this should be the counter
bysort country: replace date2=. if date2==min_date // this is to drop the observation which was counted
drop min_date //before I restart the nested loop, so that it again gets to the minimum value in `dates'
}
}
The code works without an error, but it does not do the job. Evidently there's a mistake somewhere, I am just not sure where.
BTW, it's a specific application of a problem I super often encounter: how do you count frequencies of distinct values in a multilevel data structure? This is slightly more specific, to the extent that "time matters", and it should not just sum all encounters. Let me know if you have an easier solution for this.
Thanks!
The problem with your loop is that it does not keep the replaced gov_counter after the loop. However, there is a much easier solution I'd recommend:
sort country party_id cab_date
by country party_id: gen gov_counter=sum(cabinet_party[_n-1])
This sorts the data into groups and then creates a sum by group, always up to (but not including) the current observation.
I would start here. I have stripped the comments so that we can look at the code. I have made some tiny cosmetic alterations.
foreach i of local dates {
egen min_date = min(date2)
sort country party_id date2
bysort country party_id: replace gov_counter=gov_counter+1 ///
if date2 == min_date & cabinet_party[_n-1] == 1
bysort country: replace date2 = . if date2 == min_date
drop min_date
}
This loop includes no reference to the loop index i defined in the foreach statement. So, the code is the same and completely unaffected by the loop index. The variable min_date is just a constant for the dataset and the same each time around the loop. What does depend on how many times the loop is executed is how many times the counter is incremented.
The fallacy here appears to be a false analogy with constructs in other software, in which a loop automatically spawns separate calculations for different values of a loop index.
It's not illegal for loop contents never to refer to the loop index, as is easy to see
forval j = 1/3 {
di "Hurray"
}
produces
Hurray
Hurray
Hurray
But if you want different calculations for different values of the loop index, that has to be explicit.
This is too tough for me guys. It's for Jeremy!
I have two tables (although I can also envision needing to join a third table) and I want to sum one field and count rows, in the same, table while joining with another table and return the result in json format.
First of all, the data type field that needs to be summed, is numeric(10,2) and the data is inserted as params['amount'].to_f.
The tables are expense_projects which has the name of the project and the company id and expense_items which has the company_id, item and amount (to mention just the critical columns) - the "company_id" columns are disambiguated.
So, the following code:
expense_items = DB[:expense_projects].left_join(:expense_items, :expense_project_id => :project_id).where(:project_company_id => company_id).to_a.to_json
works fine but when I add
expense_total = expense_items.sum(:amount).to_f.to_json
I get an error message which says
TypeError - no implicit conversion of Symbol into Integer:
so, the first question is why and how can this be fixed?
Then I want to join the two tables and get all the project names form the left (first table) and sum amount and count items in the second table. I have tried
DB[:expense_projects].left_join(:expense_items, :expense_items_company_id => expense_projects_company_id).count(:item).sum(:amount).to_json
and variations of this, all of which fails.
I would like a result which gets all the project names (even if there are no expense entries and returns something like:
project item_count item_amount
pr 1 7 34.87
pr 2 0 0
and so on. How can this be achieved with one query returning the result in json format?
Many thanks, guys.
Figured it out, I hope this helps somebody else:
DB[:expense_projects___p].where(:project_company_id=>user_company_id).
left_join(:expense_items___i, :expense_project_id=>:project_id).
select_group(:p__project_name).
select_more{count(:i__item_id)}.
select_more{sum(:i__amount)}.to_a.to_json
I'm trying to write an olap4j (Mondrian) query that will group the rows by ranges.
Assume we have counts of cards per child and the children ages.
i want to sum the cards amount by age ranges, so i will have counts for ages 0-5,5-10,10-15 and so on.
Is this can be done with olap4j?
You need to define calculated members for that:
With member [Age].[0-4] as [Age].[0]:[Age].[4]
member [Age].[5-9] as [Age].[5]:[Age].[9]
etc.
Alternatively, you may want to re-design your dimension table. I'm guessing you have age as a degenerate dimension in the fact table. I suggest creating a separate dimension dim_age with a structure like this:
age_id, age, age_group
0, null, null
1, 0, 0-4
2, 1, 0-4
(...)
Then it's easy to define a first level on the dimension based on the age_group.