I'm trying to apply a certain type of ranking system to my data-set and having trouble.
My Issue:
RANK() OVER(PARTITION BY Staff, Storage ORDER BY Order_Flow)
Essentially, whenever Storage 20 occurs, I want to assign a number to that row, and anything between it and the next occurrence of Storage 20 has the same number. Then from the next occurrence of Storage 20 to the next, the same thing.
My current Rank function will not accurately capture Storage 80 because it only started occurring later in the order flow.
Please view image (it can start from 1, doesn't necessarily have to start from 0).
image of example data
It looks like this can be solved using a RESET WHEN in your window function:
MAX() OVER(
PARTITION BY <...>
ORDER BY Order_Flow
RESET WHEN Storage = 20
)
I believe you can leave out the PARTITION BY if you just want to control the ordering and don't need to do any partitioning. Or just use a constant value, like PARTITION BY 1 or something to that effect.
Documentation:
https://docs.teradata.com/reader/756LNiPSFdY~4JcCCcR5Cw/8uRgqNTevlcmjBfsU3WQsw
Stackoverflow:
teradata, reset when, partition by, order by
It's a simple Cumulative Sum over a CASE:
sum(case when Storage = 20 then 1 else 0 end)
over(Partition By Staff
Order By Order_Flow
rows unbounded preceding)
Related
I am trying to simplify a table that shows the amount of time that people are working on certain jobs and wanting to present the dataset in a table that only shows the values greater than zero.
The image below shows how the table currently looks, where each person has a % of their time allocated to 1 of 5 jobs across columns.
I am trying to create a table that looks like the below, where it only shows the jobs that each person is working on, and excludes the ones where they have no % of their time allocated.
Wondering if I am going about this in the wrong fashion, any help greatly appreciated!
Thanks
I have been tryin to use an index match function with some if logic for values greater than zero but have been only able to get the first value greater than zero to populate.
time_start column holds start of conversation
time_ends column holds end of conversation, both are in time type of data in hh:mm:ss format
how can I calculate time duration between calls:
time_between_calls = time_start2 - time_end1
time_start2 - start of 2nd call
time_end1 - end of 1st call
I need to create measure which will give average of that duration for xy calls.
I don't know how to calculate this. I guess I need some kind of temporary table where I would sort dates first.
Any hint could be useful.
I forgot to add that I need to filter by agent_id first in order to get call information only for that individual agent.
So
FOR EACH agent_id do {
all above }
I've manage to solve it by following this solution.
High level overview with simple integer order value to get my point across:
id (primary) | order (sort) | attributes ..
----------------------------------------------------------
ft8df34gfx 1 ...
ft8df34gfx 2 ...
ft8df34gfx 3 ...
ft8df34gfx 4 ...
ft8df34gfx 5 ...
Usually it would be easy to change the order (e.g if user drags and drops list items on front-end): shift item around, calculate new order values and update affected items in db with new order.
Constraints:
Doesn't have all the items at once, only a subset of them (think pagination)
Update only a single item in db if single item is moved (1 item per shift)
My initial idea:
Use epoch as order and append something unique to avoid duplicate epoch times, e.g <epoch>#<something-unique-to-item>. Initial value is insertion time (default order is therefore newest first).
Client/server (whoever calculates order) knows the epoch for each item in subset of items it has.
If item is shifted, look at the epoch of previous and next item (if has previous or next - could be moved to first or last), pick a value between and update. More than 1 shifts? Repeat the process.
But..
If items are shifted enough times, epoch values get closer and closer to each other until you can't find a middleground with whole integers.
Add lots of zeroes to epoch on insert? Still reach limit at some point..
If item is shifted to first or last and there are items in previous or next page (remember, pagination), we don't know these values and can't reliably find a "value between".
Fetch 1 extra hidden item from previous and next page? Querying gets complicated..
Is this even possible? What type/value should I use as order?
DynamoDB does not allow the primary partition and sort keys to be changed for a particular item (to change them, the item would need to be deleted and recreated with the new key values), so you'll probably want to use a local or global secondary index instead.
Assuming the partition/sort keys you're mentioning are for a secondary index, I recommend storing natural numbers for the order (1, 2, 3, etc.) and then updating them as needed.
Effectively, you would have three cases to consider:
Adding a new item - You would perform a query on the secondary partition key with ScanIndexForward = false (to reverse the results order), with a projection on the "order" attribute, limited to 1 result. That will give you the maximum order value so far. The new item's order will just be this maximum value + 1.
Removing an item - It may seem unsettling at first, but you can freely remove items without touching the orders of the other items. You may have some holes in your ordering sequence, but that's ok.
Changing the order - There's not really a way around it; your application logic will need to take the list of affected items and write all of their new orders to the table. If the items used to be (A, 1), (B, 2), (C, 3) and they get changed to A, C, B, you'll need to write to both B and C to update their orders accordingly so they end up as (A, 1), (C, 2), (B, 3).
I'm am new to apex and I'm working on a food ordering application where customers are permitted to change their order details only up to 15 minutes after the order has been placed. How can I implement that ?
Create a validation on date item. Calculate difference between SYSDATE (i.e. "now") and order date. Subtracting two DATE datatype values results in number of days, so multiply it by 24 (to get hours) and by 60 (to get minutes). If that result is more than 15, raise an error.
To provide an alternative to Littlefoot's answer, timestamp arithmetic returns interval literals, if you use SYSTIMESTAMP instead your query could be:
systimestamp - order_date < interval '15' minute
or, even using SYSDATE something like:
order_date > sysdate - interval '15' minute
One note, the 15 minutes seems somewhat arbitrary (a magic number) it relies on the order not starting to be processed within that time limit. It feels more natural to say something like "you can change your order until the kitchen has started cooking it". There's no need for any magic numbers then and considerably less wastage (either of the customers time always waiting 15 minutes or of the kitchen's resources cooking something they may then have to discard).
Consider the fictional data to illustrate my problem, which contains in reality thousands of rows.
Figure 1
Each individual is characterized by values attached to A,B,C,D,E. In figure1, I show 3 individuals for which some characteristics are missing. Do you have any idea how can I get the following completed table (figure 2)?
Figure 2
With the ID in figure 1 I could have used the carryforward command to filling in the values. But since each individual has a different number of rows I don't know how to create the ID.
Edit: All individual share the characteristic "A".
Edit: the existing order of observations is informative.
To detect the change of id, the idea is to compare if the precedent value of char is >= in each rows.
This works only if your data are ordered, but it seems mandatory in your data.
gen id= 1 if (char[_n-1] >= char[_n]) | _n ==1
replace id = sum(id) if id==1
replace id = id[_n-1] if missing(id)
fillin id char
drop _fillin
If an individual as only the characteristics A and C and another individual as only the characteristics D and E, this won't work, but it seems impossible to detect with your data.