Skip to main content

Calculated Columns In Power BI

Overview
In this article, we will talk about calculated columns in Power BI. To prepare any report in real life, we must have to prepare calculated columns and measures in Power BI.

In this article, we will learn the following topics.
  1. Definition of Calculated Column
  2. How to prepare calculated column in Power BI?
  3. How do calculated columns consume memory?
  4. Advantages and disadvantages of having calculated columns
Now, let’s get started!
Calculated Columns
  • Calculated columns are the same as another database column.
  • We can prepare a new column using existing columns.
  • We can also use DAX expression to prepare a new calculated column.
  • A calculated column is applied to every single row of the dataset.
Real Life Scenario for Calculated Columns
  • For Finance Organization we can calculate P/L (Profit and Loss) operations using calculated columns.
  • For Time based operations like
  • To find our month or year from a Date, we can write calculated columns.
Steps to prepare Calculated Column in Power BI.
Step 1
There are two ways to prepare Calculated column in Power BI.
  1. Go to Modeling > Create Column.

     
  2. Go to Data view > Right click on table > Create Column.

 
Step 2
It will open a blank formula bar to write an expression.

 
Step 3
Now, let’s create a Calculated column which will calculate Total Unit Cost.
So, we will write the following formula.
  1. Total Sales Cost = Sales[SalesQuantity]*Sales[UnitCost]
As we can see, a new calculated column is created.
It is a multiplication of Sales Quantity and Unit Cost.

 
Step 4
We will create some date hierarchy. We will find out the month and the year from the date field.
For that, we will use DAX operation.

 
  1. Month = MONTH(Sales[DateKey])

Now, let’s create a Calculated column for the year.
  1. Year = YEAR(Sales[DateKey])

How do Calculated Columns consume memory?
  • When we are creating calculated columns, they are stored in memory the same way other columns are.
  • Please check the below screenshot. Total New Cost is created in a new column.

     
  • Data is refreshed in a calculated column when we refresh the data model.
Advantages
  • Supports DAX Expressions.
  • We can prepare new columns using existing data.
  • Consumes RAM instead of CPU.
  • Supports Row by Row calculation
Disadvantages
  • It consumes RAM, so if there are lots of calculated columns, it requires more memory space.
  • Data is refreshed only if we refresh the data model.
Conclusion
This is how calculated column works in Power BI. We will discuss measures in my next article.
Stay Connected with Me!

Comments

Popular posts from this blog

How to partition or split DataTable in C#?

Today we will discuss how we can divide or split a very large data table into fixed size of chunks? Scenario: Suppose there is a data table which has 1000 Rows. When you perform for each loop on data table and read each row at that time it will take too much time. If we devide 1000 Rows datatable into 10 fixed sizes (e.g. 100 Rows) datatable, It will take less time. Let's check how to achieve it. Here is a code. private static List<DataTable> SplitTable(DataTable originalTable, int batchSize) { List<DataTable> tables = new List<DataTable>(); int i = 0; int j = 1; DataTable newDt = originalTable.Clone(); newDt.TableName = "Table_" + j; newDt.Clear(); foreach (DataRow row in originalTable.Rows) { DataRow newRow = newDt.NewRow(); newRow.ItemArray = row.ItemArray; newDt.Rows.Add(newRow); i++; if (i == batchSize) ...

How To Lock Objects In Power BI

Overview Sometimes, there is a situation where when we open a report and click on any visual it accidentally nudges a chart a little bit to the right or left. Sometimes, by mistake when viewing a report, the arrangement of visuals scatters a little bit. Microsoft rolls out one new amazing feature to resolve this issue, that is, Lock Objects in Power BI. Advantages of using this feature When our purpose is to only view a report, this feature is a boon for us. Visualization’s position is not changed. Saves a lot of the developer's time to resolve the position related issues. Note   -  This feature is not saved with the report. So, every time you open a report, you need to enable this feature. Now, let’s understand this feature in a brief manner. To understand this, I will first show you one report in which I have not enabled “Lock Objects” feature. Step 1 The below screenshot shows my report which doesn’t have the enabled Lock Objects feature. ...

Create Event Calendar In Power BI

Overview In this article, we will learn how we can create Event Calendar within Power BI. We have a requirement from many of my clients to show Events within the Calendar by Category Colors. In order to achieve that requirement, we can use the custom visual from the marketplace which is “ Calendar by MAQ Software ”. You can directly download it using   URL . At the end of the article, you are able to create Event Calendar as shown in the following screenshot. We have the following data to be shown in the event Calendar. Event Start Date Event End Date Description Category   For your practice, you can download sample data source file and Power BI file using   GitHub . Let’s get started! Step 1 Import “ Calendar by MAQ Software ” from Marketplace or download using the   URL . Once it is imported we can see the visual in visualization pane. Step 2 Drag the “ Calendar by MAQ Software ” visual and set the following property. ...