How to perform LEFT JOIN on the first matching row only

[tanmay_bhardwaj]

I am performing LEFT JOIN on two tables and below are their representative layouts.

Inside my LEFT TABLE I have multiple rows for a given Key, and on my RIGHT TABLE I have only one row for the same Key.

Now I want my result such that in my resultant table, for a given Key match only the first row in my LEFT TABLE is populated with the Value (as per the image below).

Is this feasible is Qlik Sense, can someone please help guide me in this regard.

Thanks

Environment: Qlik Sense Enterprise Client Managed for Windows

Version: QlikSense May 2023

[Ravi_Nagmal · Accepted solution]

@tanmay_bhardwaj 
Add addition column in LEFT table with condition 

AutoNumber(RecNo(),Col 3) as Col 4

then create string in left table like 

Col 3 & Col 4 as Connection_String

and create same string in Right Table 

Col 3 & '1' as Connection_String

Left Join based on Connection_String and you are done

[tanmay_bhardwaj]

@Ravi_Nagmal , thanks for your help, the logic worked perfectly.