topic Re: Iterator + related function in DAX Commands and Tips

Iterator + related function

Daniel29195 — Wed, 19 Oct 2022 23:04:21 GMT

Hello,

Im confused about something , i would appreciate if someone demystify it

First question :

Does using related function inside an iterator create a transition context ?

Second question :

When creating nested iterators , first iterator im on row number 1 ,

Does the nested iterator knows the location of the outer iterator ans thus the nested iterator will be filtered based on the row context of the first iterator ?

Hope my 2 questions makes sense

Thanks for any explanation

Re: Iterator + related function

v-yueyunzh-msft — Thu, 20 Oct 2022 01:27:01 GMT

Hi , Daniel29195

Here are my understand about your question:

Q1:Does using related function inside an iterator create a transition context ?

The RELATED() function just retun a related value from another table. The RELATED function needs a row context; therefore the function often uses in the calculated column and we can use SUMX, SELECTCOLUMNS function to create a row context.

Q2:Does the nested iterator knows the location of the outer iterator ans thus the nested iterator will be filtered based on the row context of the first iterator ?

For nested iterators, this is mainly to look at the order of evaluation. Usually iterators such as FILTER(), SUMX() and other functions are iteration functions, when we use nested iterations, such as SUMX(FILTER()), then generally the FILTER() function is evaluated first, and then a table is returned, and then SUMX() iteration is performed on the generated table.

Best Regards,

Aniya Zhang

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Re: Iterator + related function

Daniel29195 — Thu, 20 Oct 2022 09:03:42 GMT

Hello v-yueyunzh-msft ,

What i meant in my questions,

What is happening behind the scenes

For the 2 questions

Like does the table in the inner iteration gets filtered by the row value of the first iteration ?

If not, then what is the logic ?

Re: Iterator + related function

v-yueyunzh-msft — Fri, 21 Oct 2022 01:20:26 GMT

Hi, Daniel29195

As I understand it, the inner iteration function returns a new table, and the outer iteration continues to iterate over the new table generated internally.

For more information, you can refer to :

Iteration in DAX - Microsoft Power BI Community

Best Regards,

Aniya Zhang

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly