How to Use Extend to Add Calculated Columns in Kusto | Kusto Query Language Tutorial (KQL)

Topic: How to Use Extend to Add Calculated Columns in Kusto Query Language.

In this article, we are going to learn about the extend operator that creates a calculated columns and append them to the result set. Azure Data Explorer is a fast, fully managed data analytics service for real-time analysis on large volumes of data streaming from applications, websites, IoT devices, and more. Ask questions and iteratively explore data on the fly to improve products, enhance customer experiences, monitor devices, and boost operations. Quickly identify patterns, anomalies, and trends in your data.

 // extend operator : Create calculated columns and append them to the result set.  
 .clear table TotalSale data   
 .create table TotalSale (  
   id: int   
   ,SalePersonFName: string  
   ,SalePersonLName : string  
   ,ProductName : string  
   ,ItemsSold : int  
   ,SoldPrice :real  
   ,SoldDate: date  
   ,City : string  
   ,State : string  
   ,Country : string  
   ,Region : string  
   )  

      //Insert data  
       .ingest inline into table TotalSale <|  
 11,Tamara,Tony,Cell Phone,2,1200,2015-03-03,Frankfurt,Hesse,Germany,Europe  
 11,Tamara,Tony,Cell Phone,2,1200,2015-03-03,Frankfurt,Hesse,Germany,Europe  
 9,Petra,Henry,TV,10,5000,2015-04-08,Paris,Île-de-France,France,Europe  
 3,Christy,Ladson,TV,3,1600,2015-04-02,High Point,NC,USA,North America  
 7,Chirag,Patel,Cell Phone,5,1500,2015-06-23,AhmadAbad,Gujrat,India,Asia  
 2,M,Raza,Cell Phone,2,800,2015-07-15,Charlotte,NC,USA,North America  
 5,Najaf,Ali,Computer,1,300,2015-06-20,Karachi,Sindh,Pakistan,Asia  
 6,Sukhjeet,Singh,TV,2,900,2015-06-21,ChandiGar,Punjab,India,Asia  
 4,John,Rivers,Laptop,5,2400,2014-03-09,Jersey City,NJ,USA,North America  
 8,Aleena,Aman,Laptop,2,800,2015-05-25,Lahore,Punjab,Pakistan,Asia  
 10,Rita,Roger,Laptop,7,2100,2015-04-11,Paris,Île-de-France,France,Europe  
 1,Aamir,Shahzad,TV,1,700,2015-07-15,Charlotte,NC,USA,North America  
 12,aamir,shahzad,TV,1,7000,2015-07-15,Charlotte,NC,USA,North America  
 id=Null,bisma,Roger,Laptop,7,2100,2015-04-11,Paris,Île-de-France,France,Europe  

 // extend operator : Create calculated columns and append them to the result set.  
 //get all columns with data from table  
 TotalSale  

 //add a calculated columns  
 TotalSale  
 | extend fullname=strcat(SalePersonLName,' ',SalePersonLName),DayofYear=dayofyear(SoldDate)  

 // extend the columns to result set  
 TotalSale  
 | project id,SalePersonFName,SalePersonLName,ItemsSold, SoldDate  
 | extend fullname=strcat(SalePersonLName,' ',SalePersonLName),DayofYear=dayofyear(SoldDate)  

Video Demo: How to Use Extend to Add Calculated Columns in Kusto | Kusto Query Language Tutorial (KQL)