Converting a Case Transform in ADF Mapping DataFlow

Question

I am currently building a DF in ADF where i am converting the below Query which is already placed in another ETL tool called BigDecission. The Query looks like below

SELECT
    Asset_ID,
    MAX(CASE WHEN meter = 'LTPC' THEN reading_date ELSE NULL END) AS LTPC_Date,
    MAX(CASE WHEN meter = 'LTPC' THEN page_Count ELSE NULL END) AS LTPC,
  
FROM
    mv_latest_asset_read
GROUP BY
    Asset_ID

While converting this piece in ADF DF i have used AGGREGATE transform and done GROUP BY "ASSET_ID". In the AGGREGATES Tab i am deriving the column "LTPC_DATE" and "LTPC" with below mentioned code.

LTPC_DATE ---- > max(case(METER=='LTPC',READING_DATE))

LTPC ---- > max(case(METER=='LTPC',PAGE_COUNT))

But in the output i am getting null values which shouldn't be the case. Can anyone identify the right way to do it.

Answer 1

I followed the same approach to reproduced above and getting proper result.

Please check the below:

My source data:

Here I have taken 2 additional columns using derived column transformation and giving a sample value.

Group By and aggregate:

Used max(case(condtion,expression)) here.

Result in Data preview:

Try to check your projection in the source. Also, transform this to a sink file and check if it gives correct result or not.

If it still gives same, you can try maxIf(condition, expression) as suggested by @Mark Kromer MSFT .

The above also giving the same result for me.

If your source is a database, you can try query option in the source of dataflow and give the above query.

After Importing projection, you can see the desired result in the Data preview.