DAX (Data Analysis Expression), An Essential Language for PowerBI
Mr. Thu Ta Naing (Microsoft Certified Trainer 2021–2022)
Sat wat dii thuk khon!!., Welcome back na khrub!, today we will talk about DAX, that every Data Analysts Student should know in using PowerBI.
Now, Lets' check out, what are these ??
Simply put, DAX, stands for Data Analysis Expressions, in which we mainly use them to extract
(1) our Business Insights,
(2) the details and specific information from our Business Datasets, as well as
(3) finding out the Relationship Patterns between Data, and
(4) even comparing our Business Calculations over a different timeframe!
So na khrub!!, it's clear that we should learn DAX ASAP (As soon as possible) right ?
Ok then, let me introduce how many DAX Calculation types we can use in PowerBI ? NOW, let's go!
Actually, we can say that DAX can be used in 4 Areas: (1) Measures, (2) Calculated Columns, (3) Calculated Tables, (4) Row-Level Security… na khrub!!
Wait!!, what are these ?? , these are NEW to me ??
Ok,.. let's see ONE by ONE now..
(1) Measures: ==> Yes, we call that Measures, if u are learning Data Analytics Technologies in PowerBI na khrub!., To understand about Measures, let's look the picture below..
In this figure below, I have developed the Total Sales using Card Visual in PowerBI. So to produce these kind of results, we use Measures na khub! Especially Aggregation functions like SUM, COUNT, MAX, MIN etc.., are used in these kind of calculations na khrub!!
Yes!!, they are very useful in Developing PowerBI Report.., because without these we cannot efficiently produce these results in PowerBI na khrub!
Now, follow me!, lets see another one => Calculated Columns!
(2) Calculated Columns ==> Unlike Measures above ( I mean Different from Measures above), we use Calculated Columns in a different way. As included in the name, we use "Calculated Columns" to create new columns in PowerBI na khrub!! ..
For example, Let's look at the below figure.. , here, Our Original Datasets only have 4 Columns => "Name", "City", "Date of Birth", "Number of children" na khrub!
But, now, if we want to add a new column based on condition values of existing column values, we can use "Calculated Columns". That's where we apply this technique na khrub!.
(3) Calculated Tables ==> However, if we want to create Tables.. in PowerBI, we can use DAX Formulas in Calculated Tables na khub!. This can be used in situations when we want to create a new Table from existing Data Source Tables na khub!.
(Details will be explained in next post na khub!)
(4) Row-Level Security ==> In short terms, we call it "RLS". It's a kind of advanced topic on Securing our Report Data, so that only Authorized person users/ accounts can view their related information na khub!.
For example , even in the same Report, Sales Manager in Chonburi can only see Chonburi Sales, while Bangkok Sales Manager can only sales related with Bangkok Division. That's how we can control and restrict the permissions na khub!.
Now, thats all for today na khub!, I am learning Thai Language, day by day, and hopefully, can also explain in Thai language in coming future na khub!.
See u later!! thuk khun!!
Thu Ta Naing
Microsoft Certified Trainer (MCT 2021–2022)