Django: Periodic increment to all records in one field - django

Is there a more efficient way of incrementing all records of a field every hour besides running a task that loops through all records at set time intervals and individually updates all records?
For example, User_profile Model:
username | coins_bought | coins_free | coins_spent
Amadeus | 0 | 0 | 0 <-- new user has 0 coins throughout
Ludwig | 5 | 5 | 3
Elise | 21 | 9 | 12 <-- old user with prior activity
1 hr later:
username | coins_bought | coins_free | coins_spent
Amadeus | 0 | 0+1 | 0
Ludwig | 5 | 5+1 | 3
Elise | 21 | 9+1 | 12
5 hr later:
username | coins_bought | coins_free | coins_spent
Amadeus | 0 | 5 | 0
Ludwig | 5 | 10 | 3
Elise | 21 | 14 | 12
In this example, users can buy coins or wait 1 hour until they all receive a free coin and can use in on the web-app. I can't make this feature client side, because it's not a mobile app, and caching is easy to corrupt.
Edit: I found the solution, if anyone else is stuck on this view this link
You can run an update method on a queryset as such at set time interval:
Model.object.all().update(same_field=F('same_field')+1)


One option would be to use an update query which could be run from a scheduled task controlled by Celery. Celery's documentation is pretty good on this: https://docs.celeryproject.org/en/stable/userguide/periodic-tasks.html

Related

how to make a query in sql to use in c++ code on counting the borrowing report in every month

I want to make a query to count borrowing report every month . But i'd saved my data in unixtime.
tablename:borrow
attributes:borrowingID,dateOfBorrow,dateOfReturn,statusBook
For example the dateOfBorrow is 167077440 and i just want to count the specific month for jan,feb,etc..
i am expecting
| Month | Total |
| ------| ----- |
| Jan | 2 |
| Feb | 5 |
| Mar | 5 |
...etc

select from_unixtime(167077440),from_unixtime(167077440,'%b')
+--------------------------+-------------------------------+
| from_unixtime(167077440) | from_unixtime(167077440,'%b') |
+--------------------------+-------------------------------+
| 1975-04-18 19:24:00 | Apr |
+--------------------------+-------------------------------+
1 row in set (0.001 sec)
See manual https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_from-unixtime and https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_date-format
But are you really interested in 1975?

Single Filter for PowerBI

I have 2 tables in powerbi, one contains all transactions to and from people (each client identified with an id, where "I" can be either the receiver or sender of $) and the other is the detail for each client.
Table 1 would look something like
| $ | sender id | receiver id |
|---|-----------| ------------|
| 10| 1 | 2 |
| 15| 1 | 3 |
| 20| 1 | 2 |
| 15| 3 | 1 |
| 10| 3 | 1 |
| 25| 2 | 1 |
| 10| 1 | 2 |
The second table contains sender id and name:
| id | name |
|----|-------|
| 1 | "me" |
| 2 | John |
| 3 | Susan |
The expected result is something like (not necesarily in a table, just to show)
| $ sent | $ received | Balance|
|--------|------------|--------|
| 55 | 45 | +10 |
And in a filter have "John" and "Susan" so when i Select one of them i could see $ sent, $received and balance for each of them.
The problem of course is that i end up with one active and one inactive relationship so if i apply such a filter i end up with 0 in sender/receiver and the whole value in the other (depending which is made active and inactive) and if i make another table that's "id sender"+"name sender" then i cant filter all at once.
Is it possible to do this?
I hope this is kinda understandable

You will need to add 2 columns to your user table
received = CALCULATE(SUM(T1[$]), Filter(T1, UserTable[id] = T1[reveicer id]))
The same you can do for send. Now in your visual, use the new columns.
Enjoy!

after going around a bit I found a way to solve this, probably not the most orthodox way to do it, but it works.
What I did is to add 2 columns to my sales table, one was labeled "movement" and in sql it is just a 'case' where when the receiver is 'me' its "Charged" and when the receiver is 'not-me' its "Payment", then i added a column with a case so it would always bring me the 'not-me' id, and i used that for may relationship with my users table.
Then I just added filters in my cards making one a "Payment" card and the other a "Charged" card.
This is all following the previous example, it was actually just a bit more tricky as I could actually have a payment from me to myself, but thats just another "case" for when it was 'me-me'
Hope this is understandable, english is not my first language and the information i actually used is partially confidential so i had to make the above example.
thanks all and have a nice day.

PowerBI: Use non-shown values for Drillthrough

I am trying to build a Power BI report for data from a SQL database where I have to show detail pages using Drillthrough. The only viable way to connect the datasets is using the database row ids.
From a user's perspective the row ids would not add any value but a lot of noise.
Is there a way to drillthrough using the row ids without showing them in a visual?

Yes, this is possible in the current release of Power Bi Desktop using a workaround solution that involves hiding the row id column in the parent (or summary) page.
Take the following tables as example:
ALBUM
+---------+------------------------+
| AlbumId | AlbumName |
+---------+------------------------+
| 1 | Hoist |
+---------+------------------------+
| 2 | The Story Of the Ghost |
+---------+------------------------+
TRACK
+---------+---------+--------------------------+
| TrackId | AlbumId | TrackName |
+---------+---------+--------------------------+
| 1 | 1 | Julius |
+---------+---------+--------------------------+
| 2 | 1 | Down With Disease |
+---------+---------+--------------------------+
| 3 | 1 | If I Could |
+---------+---------+--------------------------+
| 4 | 1 | Riker's Mailbox |
+---------+---------+--------------------------+
| 5 | 1 | Axilla, Part II |
+---------+---------+--------------------------+
| 6 | 1 | Lifeboy |
+---------+---------+--------------------------+
| 7 | 1 | Sample In a Jar |
+---------+---------+--------------------------+
| 8 | 1 | Wolfmans Brother |
+---------+---------+--------------------------+
| 9 | 1 | Scent of a Mule |
+---------+---------+--------------------------+
| 10 | 1 | Dog Faced Boy |
+---------+---------+--------------------------+
| 11 | 1 | Demand |
+---------+---------+--------------------------+
| 12 | 2 | Ghost |
+---------+---------+--------------------------+
| 13 | 2 | Birds of a Feather |
+---------+---------+--------------------------+
| 14 | 2 | Meat |
+---------+---------+--------------------------+
| 15 | 2 | Guyute |
+---------+---------+--------------------------+
| 16 | 2 | Fikus |
+---------+---------+--------------------------+
| 17 | 2 | Shafty |
+---------+---------+--------------------------+
| 18 | 2 | Limb by Limb |
+---------+---------+--------------------------+
| 19 | 2 | Frankie Says |
+---------+---------+--------------------------+
| 20 | 2 | Brian and Robert |
+---------+---------+--------------------------+
| 21 | 2 | Water in the Sky |
+---------+---------+--------------------------+
| 22 | 2 | Roggae |
+---------+---------+--------------------------+
| 23 | 2 | Wading in the Velvet Sea |
+---------+---------+--------------------------+
| 24 | 2 | The Moma Dance |
+---------+---------+--------------------------+
| 25 | 2 | End of Session |
+---------+---------+--------------------------+
Add them as data sources. The 1:many relationship between AlbumId should be created. Create a parent page with a table containing AlbumId and AlbumName. Then create the details page with a table containing only the TrackName column. In the Drillthrough filter field of the details page, drag the Album Table -> AlbumId to this field.
Now go back to the parent page and notice that when you right click on an album, you get the drillthrough menu to the details page. This works, but now you have a messy AlbumId column on your parent page.
The workaround is to hide the AlbumId on the parent report. First go to the Format(Paint roller) menu of the table on the parent report and in the column header -> word wrap turn this off. Then drag the column separator of the table to hide the AlbumId. See before and after images below.
BEFORE HIDE
AFTER HIDE
I have the powerbi file posted here if you want to see it in action.

Power Bi create comma seperated list string where ids match

Im really new to Power Bi, I created the following table:
ID | POST_ID |
0 | 11 |
0 | 12 |
0 | 13 |
0 | 18 |
0 | 21 |
1 | 14 |
1 | 15 |
2 | 16 |
2 | 17 |
2 | 19 |
2 | 20 |
Now I need to pass this ids to an api as a comma seperated list, so I want to transform the table to:
ID | POST_ID |
0 | 11,12,13,18,21 |
1 | 14,15 |
2 | 16,17,19,20 |
But can't manage to do this. I assume it must be fairly easy to do? I have no clue to start, I've been messing around in the query editor now for a few hours and googling wont bring me much help either so far!
Thanks in advance!

Here is a solution
let
t=#table({"ID", "POST_ID"},{{0, 11},{0, 12},{0, 13},{0, 18},{0, 21},{1, 14},{1, 15},{2, 16},{2, 17},{2, 19},{2, 20}}),
group = Table.Group(t, {"ID"}, {{"val_list", each Text.Combine(List.Transform([POST_ID], Number.ToText), ",")}})
in
group
But... are you sure you finally need a text string?
If you pass result to API, perhaps you'd better pass a list of numbers
So your code should look like this
let
t=#table({"ID", "POST_ID"},{{0, 11},{0, 12},{0, 13},{0, 18},{0, 21},{1, 14},{1, 15},{2, 16},{2, 17},{2, 19},{2, 20}}),
group = Table.Group(t, {"ID"}, {{"val_list", each [POST_ID]}})
in
group

How to run raw query with a model with dynamic fields in Django 1.9?

I have a complex result that requires writing raw sql queries.
See https://stackoverflow.com/a/38548462/80353
The expected result is a table showing several columns.
The first column header is simply Product and the other column headers are store names.
The values are simply the product names and the aggregated sales values of the product in these stores.
Which stores will be shown is entirely dynamic. Maximum should be 9 stores.
The same in text format:
Store table
------------------------------
| id | code | address |
|-----|------|---------------|
| 1 | S1 | Kings Row |
| 2 | S2 | Queens Street |
| 3 | S3 | Jacks Place |
| 4 | S4 | Diamonds Alley|
| 5 | S5 | Hearts Road |
------------------------------
Product table
------------------------------
| id | code | name |
|-----|------|---------------|
| 1 | P1 | Saucer 12 |
| 2 | P2 | Plate 15 |
| 3 | P3 | Saucer 13 |
| 4 | P4 | Saucer 14 |
| 5 | P5 | Plate 16 |
| and many more .... |
|1000 |P1000 | Bowl 25 |
|----------------------------|
Sales table
----------------------------------------
| id | product_id | store_id | amount |
|-----|------------|----------|--------|
| 1 | 1 | 1 |7.05 |
| 2 | 1 | 2 |9.00 |
| 3 | 2 | 3 |1.00 |
| 4 | 2 | 3 |1.00 |
| 5 | 2 | 5 |1.00 |
| and many more .... |
| 1000| 20 | 4 |1.00 |
|--------------------------------------|
The relationships are:
Sales belongs to Store
Sales belongs to Product
Store has many Sales
Product has many Sales
What I want to achieve
I want to display by pagination in the following manner:
Given the stores S1-S3:
-------------------------
| product | S1 | S2 | S3 |
|---------|----|----|----|
|Saucer 12|7.05|9 | 0 |
|Plate 15 |0 |0 | 2 |
| and many more .... |
|------------------------|
For more details of the schema, check the question in How to get back aggregate values across 2 dimensions using Python Cubes?
My question
The schema is not super important to my question which is:
Since I am going to write a complex raw query, is there a way to map the query result to a model where the fields are dynamic?
I found documentation about how to execute raw queries in Django and how to execute raw queries to existing models with fixed fields and matching table.
My question is is it possible to do that for a model that has no matching table and dynamic fields?
If so, how?
Or if I choose to use materialised view in postgresql, how do I match it with a model class?