DAX COUNT/COUNTA functions - dax

I've looked at many threads regarding COUNT and COUNTA, but I can't seem to figure out how to use it correctly.
I am new to DAX and am learning my way around. I have attempted to look this up and have gotten a little ways to where I need to be but not exactly. I think I am confused about how to apply a filter.
Here's the situation:
Four separate queries used to generate the data in the report; but only need to use two for the DAX function (Products and Display).
I have three columns I need to filter by, as follows:
Customer (Display or Products query; can do either)
Brand (Products query)
Location (Display query)
I want to count the columns based on if the data is unique.
Here's an example:
Customer: Big Box Buy;
Item: Lego Big Blocks;
Brand: Lego;
Location: Toys;
BREAK
Customer: Big Box Buy;
Item: Lego Star Wars;
Brand: Lego;
Location: Toys;
BREAK
Customer: Big Box Buy;
Item: Surface Pro;
Brand: Microsoft;
Location: Electronics;
BREAK
Customer: Little Shop on the Corner;
Item: Red Bicycle;
Brand: Trek;
Location: Racks;
In this example, no matter the fact that the items are different, we want to look at just the customer, the brand, and the location. We see in the first two records, the customer is "Big Box Buy" and the brand is "Lego" and the location is "Toys". This appears twice, but I want to count it distinct as "1". The next "Big Box Buy" store has the brand "Microsoft" and the location is "Electronics". It appears once and only once, and thus the distinct count is "1" anyway. This means that there are two separate entries for "Big Box Buy", both with a count of 1. And lastly there is "Little Shop on the Corner" which appears just once and is counted just once.
The "skeleton" of the code I have is basically just to see if I can get a count to work at all, which I can. It's the FILTER that I think is the problem (not used in the below example) judging by other threads I've read.
TotalDisplays = CALCULATE(COUNTA(products[Brand]))
Obviously I can't just count the amount of times a brand appears as that would give me duplicates. I need it unique based on if the following conditions are met:
Customer must be the same
Brand must be the same
Location must be the same
If so, we distinctly count it as one.
I know I ranted a bit and may seem to have gone in circles, but I was trying to figure out how to explain it. Please let me know if I need to edit this post or post clarification.
Many thanks in advance as I go through my journey with DAX!

I believe I have the answer. I used a NATURALINNERJOIN in DAX to create a new, merged table since I needed to reference all values in the same query (couldn't figure out how to do it otherwise). I also created an "unique identity" calculated column that combined data from multiple rows, but was hidden behind the scenes (not actually displayed on the report) so I could then take a measure of the unique values that way.
TotalDisplays = COUNTROWS(DISTINCT('GD-DP-Merge'[DisplayCountCalcCol]))
My calculated column is as follows:
DisplayCountCalcCol = 'GD-DP-Merge'[CustID] & 'GD-DP-Merge'[Brand] & 'GD-DP-Merge'[Location] & 'GD-DP-Merge'[Order#]
So the measure TotalDisplays now reports back the distinct count of rows based on the unique value of the customer ID, the brand, and the location of the item. I also threw in an order number just in case.
Thanks!

I am semi new to DAX and was struggling with Count and CountA formula, you post has helped me with answers. I would like to add the solution which i got for my query: Wanted count for Right Time start Achieved hence if anyone is looking for this kind of answer use below, filter will be selecting the table and adding string which you want to
RTSA:=calculate(COUNTA([RTS]),VEO_Daily_Services[RTS]="RTSA")

Related

How to create a DAX cross-sectional measure?

I don't know if I even worded the question correctly, but I'm trying to create a measure that depends on what is showing in the pivot table (using PowerPivot). In the image I posted, "DealMonth" is an expression in the PowerQuery table itself that simply takes the start date of the employee and subtracts it from the month a deal was closed in. That will show how long it took for that salesperson to close the deal. "TenureMonths" is also an expression in the PowerQuery table that calculates the tenure of the person. The values populating this screenshot are coming from a total headcount measure created. What I'm trying to do is create a separate measure that will show when the "TenureMonths" is less than the "DealMonth." So if the TenureMonths is 5, then after DealMonth of 5, the value would be 0. Is this possible?
Screenshot
I should add the following information.
"DealMonth" - Comes from the FactData table
"TenureMonths" - Comes from the DimSalesStart table
These two tables are joined by name. I feel like I'm so close because I can see what I want. The second image below is a copy/paste of the pivot table result but with my edits to show what I'd want to have shown. Basically, if(TenureMonths >= DealMonth,1,0). The trouble seems to be that since they're in two different tables, I can't make it work. The rows in the fact table are transactions, but the rows in the dim table are just the people with their start and end dates.
Desired Result
This is possible with some IF([measure1]<[measure2],blank(),[measure1]), however without seeing more of the data it will be hard to guide you specifically.
However you need to create two separate measures, one for TenureMonths and one for DealMonth, depending on the data this can be done with an aggregator forumla such as sum, min, max, etc (depends if there will be more than one value).
Then reference those two measures in the formula pattern I mentioned above, and that should give you want you want.
I figured out a solution. I added a dimension table for DealMonth itself and joined to my fact table. That allowed me to do the formulas that I needed.

Swapping rows and columns in a matrix in Power BI

I want to analyse the sales of a certain company in Power Bi. I have a customer dataset with nine columns (gender, city, age range, hair colour etc.) and one million records. Now I want to put those columns in a matrix. For instance:
Rows: Gender
Columns: Age Range (<16, 17-20, 21-25 etc.)
Values: Number of Sales
I present this dashboard towards some people and I want to 'play' with the data. What happens if I change the rows to 'hair colour' for instance. Is there a way to do this without using bookmarks? In one sentence: swapping rows and columns of a matrix while you present the dashboard and cannot use the option 'Fields'? Or at least point me in the right direction? It would really help me. Thanks in advance!
Unfortunately, the quickest way to do this is using the Fields pane. The only other option that is available would be Bookmarks, but I guess you have already tried that. I guess you are an option similar to the one available in "Pivot Charts" where you can "Switch Rows/Columns" with the click of a button. That option is not available in Power BI at this point, as far as I know.

Qlik sense - Rank() within a specific dimension when you have multiple ones

I am new to Qlik and trying to solve the following issue.
I have a table with two dimensions, one with the entry's unique ID, and one with a category, as in the example below.
Table example
My goal is to create a new column with a ranking of 'Score' - my measure - per category:
Table with desired output
If I use the expression
Rank(Score)
I get a column of ones, as the command takes the most granular dimension (Unique ID) as the default one. If I use
Rank(TOTAL Score)
It obviously returns a ranking regardless of all the dimensions. By reading the documentation and similar questions asked by other users I reckon that it should be possible to specify which dimension to use for TOTAL, with the following syntax:
Rank(TOTAL <Category> Score)
Yet, the formula returns an error and only null column values. I've tried different syntax, use of brackets but I still cannot grasp what I am doing wrong.
Please note that I cannot create the ranking column when loading the data.
I would immensely appreciate if someone were so kind to help on this!
Try with
=aggr(rank(sum(Score)), Category, UniqueID)

Not getting the correct totals using Cognos Report Studio. Need to get totals that show up in column

newparts_calc
if (([MonthToDateQuery].[G/L Account] = 4200 and [Query1].[G_L_Group] = 'NEW')) THEN ([Credit Amount]-[Debit Amount]) ELSE (0)
Data Item1
total([newparts_calc])
I need Data Item1 to return newparts_calc values only.
So for example in 1st row Data Item1 should be 8,540.8, but is 34,163.2
Whats wrong? how do i fix?
REVISED QUESTION
I apologize for not making sense on the original question.
I have many of the calc's that im trying to gather and put on a crosstab. I want to see sales by month (row) and part category (column)
[Query2] is the one shown in picture above.
It joins [MonthToDateQuery] AND [Query1]
The join is on 'Invoice' and carnality is 1..1 = 1..1
[MonthToDateQuery] is based on the package im working in. General ledger. It supplies the g/l entries for each sales g/l account
[Query1] is a SQL query i brought in to be able to break out categories even further from g/l group.
For example g/l account 4300 is rebuilt. However i needed to break out even further to see Rebuilt-Production and Rebuilt-New. I can do that with the g/l group.
I saw in my g/l account ledger entries that it referenced the invoice number. So thats how i tied in my SQL.
So as you can see from the table below (which is the view tabular data from query) i need a total. I have tried plugging newparts_calc into my crosstab and setting aggregation to total but the numbers still dont seem right. I dont think i have something set as it should be.
All the calc's im doing are based on single or multiple G/L Accounts and single or multiple G/L Groups.
Any Advice?
As you can see the problem seems to be duplicate invoice numbers.
How can i fix?
Couple things come to mind:
-Set the processing order to 2
-Since your calc is always a multiple and you are joining two queries, you may need to check your cardinality. Sometimes it helps to add derived queries to ensure you are working with the correct grain.
I'm obviously missing something, but if you want
I need Data Item1 to return newparts_calc values only.
just use newparts_calc, without total? That would give you proper value for row 1 -)
If you need a running-total for days (sum of values for previous days) — you should use a running_total function.
At a guess, one of your two queries is returning multiple rows for each invoice, which will cause this double counting. Look at the output of the two queries and see if that's happening. If so, then you just need to work out how to collapse that down to one row per invoice.
Per your new question - The underlying data has got to be causing the issue. Its clearly not 1:1 (note that even though this is what your stated cardinality is, Cognos does not enforce 1:1). Invoice number is not unique, GL Group is at a lower level.

Random exhaustive (non-repeating) selection from a large pool of entries

Suppose I have a large (300-500k) collection of text documents stored in the relational database. Each document can belong to one or more (up to six) categories. I need users to be able to randomly select documents in a specific category so that a single entity is never repeated, much like how StumbleUpon works.
I don't really see a way I could implement this using slow NOT IN queries with large amount of users and documents, so I figured I might need to implement some custom data structure for this purpose. Perhaps there is already a paper describing some algorithm that might be adapted to my needs?
Currently I'm considering the following approach:
Read all the entries from the database
Create a linked list based index for each category from the IDs of documents belonging to the this category. Shuffle it
Create a Bloom Filter containing all of the entries viewed by a particular user
Traverse the index using the iterator, randomly select items using Bloom Filter to pick not viewed items.
If you track via a table what entries that the user has seen... try this. And I'm going to use mysql because that's the quickest example I can think of but the gist should be clear.
On a link being 'used'...
insert into viewed (userid, url_id) values ("jj", 123)
On looking for a link...
select p.url_id
from pages p left join viewed v on v.url_id = p.url_id
where v.url_id is null
order by rand()
limit 1
This causes the database to go ahead and do a 1 for 1 join, and your limiting your query to return only one entry that the user has not seen yet.
Just a suggestion.
Edit: It is possible to make this one operation but there's no guarantee that the url will be passed successfully to the user.
It depend on how users get it's random entries.
Option 1:
A user is paging some entities and stop after couple of them. for example the user see the current random entity and then moving to the next one, read it and continue it couple of times and that's it.
in the next time this user (or another) get an entity from this category the entities that already viewed is clear and you can return an already viewed entity.
in that option I would recommend save a (hash) set of already viewed entities id and every time user ask for a random entity- randomally choose it from the DB and check if not already in the set.
because the set is so small and your data is so big, the chance that you get an already viewed id is so small, that it will take O(1) most of the time.
Option 2:
A user is paging in the entities and the viewed entities are saving between all users and every time user visit your page.
in that case you probably use all the entities in each category and saving all the viewed entites + check whether a entity is viewed will take some time.
In that option I would get all the ids for this topic- shuffle them and store it in a linked list. when you want to get a random not viewed entity- just get the head of the list and delete it (O(1)).
I assume that for any given <user, category> pair, the number of documents viewed is pretty small relative to the total number of documents available in that category.
So can you just store indexed triples <user, category, document> indicating which documents have been viewed, and then just take an optimistic approach with respect to randomly selected documents? In the vast majority of cases, the randomly selected document will be unread by the user. And you can check quickly because the triples are indexed.
I would opt for a pseudorandom approach:
1.) Determine number of elements in category to be viewed (SELECT COUNT(*) WHERE ...)
2.) Pick a random number in range 1 ... count.
3.) Select a single document (SELECT * FROM ... WHERE [same as when counting] ORDER BY [generate stable order]. Depending on the SQL dialect in use, there are different clauses that can be used to retrieve only the part of the result set you want (MySQL LIMIT clause, SQLServer TOP clause etc.)
If the number of documents is large the chance serving the same user the same document twice is neglibly small. Using the scheme described above you don't have to store any state information at all.
You may want to consider a nosql solution like Apache Cassandra. These seem to be ideally suited to your needs. There are many ways to design the algorithm you need in an environment where you can easily add new columns to a table (column family) on the fly, with excellent support for a very sparsely populated table.
edit: one of many possible solutions below:
create a CF(column family ie table) for each category (creating these on-the-fly is quite easy).
Add a row to each category CF for each document belonging to the category.
Whenever a user hits a document, you add a column with named and set it to true to the row. Obviously this table will be huge with millions of columns and probably quite sparsely populated, but no problem, reading this is still constant time.
Now finding a new document for a user in a category is simply a matter of selecting any result from select * where == null.
You should get constant time writes and reads, amazing scalability, etc if you can accept Cassandra's "eventually consistent" model (ie, it is not mission critical that a user never get a duplicate document)
I've solved similar in the past by indexing the relational database into a document oriented form using Apache Lucene. This was before the recent rise of NoSQL servers and is basically the same thing, but it's still a valid alternative approach.
You would create a Lucene Document for each of your texts with a textId (relational database id) field and multi valued categoryId and userId fields. Populate the categoryId field appropriately. When a user reads a text, add their id to the userId field. A simple query will return the set of documents with a given categoryId and without a given userId - pick one randomly and display it.
Store a users past X selections in a cookie or something.
Return the last selections to the server with the users new criteria
Randomly choose one of the texts satisfying the criteria until it is not a member of the last X selections of the user.
Return this choice of text and update the list of last X selections.
I would experiment to find the best value of X but I have in mind something like an X of say 16?

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