topic SQL CTE in Databricks or something similar? in Data Engineering

SQL CTE in Databricks or something similar?

gbradley145 — Fri, 07 Oct 2022 14:24:25 GMT

%sql

WITH genCTE AS (

SELECT MAX(PredID) + 1 AS PredID, 145 AS SystemID

FROM TableA

UNION ALL

SELECT PredID + 1

FROM genCTE

)

SELECT * FROM genCTE

When I attempt this, I get an error that genCTE does not exists.

There may be a better way to what I am trying to do. Currently in the version of databricks we are running, we cant use an identity column. We are migrating a table and job from SQL Server to databricks. I can do a full load and pull over the identity column. But, I need to continue to populate this identity column going forward.

I also have a tried a SQL UDF where I can easily grab the MAX(ID) and have tried a row_number function over the top of it, but I cant get it work.

Hopefully I have done an adequate job of describing this issue. I simply need continue the IDs and need to do it programmaticly in databricks. I am hoping I can do this via SQL as well as I am not at all familiar with Python, although I would be open to a Python solution, I would just need a little more hand holding with it.

Thank you!

Re: SQL CTE in Databricks or something similar?

byrdman — Sun, 09 Oct 2022 17:27:16 GMT

not seeing anything wrong , but know that your close to making this work.. I do use CTE's in Databricks SQL. make sure your query works as expected outside the CTE. another work around is make the cte portion into a dataframe then create a view from the dataframe, and use it for joins in your sql statement.

Re: SQL CTE in Databricks or something similar?

PriyaAnanthram — Mon, 10 Oct 2022 02:39:37 GMT

Recursive CTEs I havent yet used I got the below eg working with pyspark code How to implement Recursive Queries in Spark | by Akash Chaurasia | Globant | Medium

Re: SQL CTE in Databricks or something similar?

Hubert-Dudek — Sun, 16 Oct 2022 10:22:46 GMT

You are referencing CTE inside of CTE. That's why it is not working. It would be best if you refactored your query.

Re: SQL CTE in Databricks or something similar?

Anonymous — Thu, 17 Nov 2022 03:50:03 GMT

Hi @Greg Bradley

Hope all is well! Just wanted to check in if you were able to resolve your issue and would you be happy to share the solution or mark an answer as best? Else please let us know if you need more help.

We'd love to hear from you.

Thanks!