Data Factory Join Transformation showing Null Values instead matching records

Hemanath Goud Kandula 1 Reputation point

I am joining two different tables using Azure Data Factory with Data Flow Activity.

In Data Flow Activity I am using Join Function For joining two tables with column having same Values.

While joining these columns the output is returning as null for one of the in put table and as well it is not showing any matching records in between them.

The Table which i am trying to join other table returning null in data preview of join even if you inner join or left outer join.

This will be joining two tables with Left outer join

This will joining two table with left outer join

This will be joining two tables with inner joinScreenshot 2023-05-29 121156

This will be the output of matching table in the data preview just showing null values.Screenshot 2023-05-29 121357

When i see the projection of matching table it has values.

Screenshot 2023-05-29 122017

Can someone help me to resolve this issue please.

Azure SQL Database
Azure Data Factory
Azure Data Factory
An Azure service for ingesting, preparing, and transforming data at scale.
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  1. Vahid Ghafarpour 20,495 Reputation points

    It seems you want to match 1 with 01 and because data types differ, the join operation may not produce the desired results. I suggest to use internal functions to convert to same data type and after converting the data types of both streams to target format, you can use the Join transformation in your Azure Data Factory Data Flow to perform the join operation. Ensure that you select the appropriate join type (e.g., inner join, left join, etc.) based on your requirements.

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  2. ShaktiSingh-MSFT 14,381 Reputation points Microsoft Employee

    Hemanath Goud Kandula

    Thanks for providing the information.

    For Oracle as Source in Data Flow Activity, it is currently not supported in ADF.

    For list of connectors and support refer to

    Currently Oracle is supported with Copy Activity as Source/Sink and in Lookup Activity.

    For this, I would recommend you to share your valuable feedback for this feature enablement over Azure Data Factory Feedback Channel where concerned team will look into the requests and prioritize on the basis of importance and up-votes.

    As a workaround, consider using Copy Activity to take data to Azure and then use Data Flow activity.

    Hope this helps. Please let us know if you have further queries.

    Thank you.

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