FOR WHILE loops in dataflows

jaeW_at_Onyx

Related to: https://dojo.domo.com/main/discussion/52378/is-it-possible-to-use-while-do-loops-in-mysql-in-domo-dataflows

There is no way to implement SQL Recursive Queries in Domo: https://www.sqlservertutorial.net/sql-server-basics/sql-server-recursive-cte/

Instead you have to guess the max depth and build as many JOINs and columns manually into your Queries / Dataflows.

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It would be ideal to have a mechanism for executing a FOR / WHILE loop in dataflows.

Use cases for my organization include, we have a writeback connector that due to the vendor's API restraints can only receive 1M rows at a time.

If we knew our dataflow could have up to 7M rows, we'd have to implement 7 writeback connectors in the dataflow each with a LIMIT / OFFSET function built in.

Ideal state would be to do a FOR WHILE loop that would handle pagination.

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If you were doing any sort of bill of materials reporting and you wanted to structure your data so that you knew "for each recipie which items are part of this recipie" you would have to know the maximum depth of all work-in-progress recipies.

ex. I want to know all the components of a Subaru Forester. I'd need to know the components of an engine. each engine is composed of pistons... and stuff. each piston is composed of ... gaskets and rods. each gasket is made from ... stuff. In order to build a report that captures the full BOM i'd have to know the depth each WIP goes to.

jaeW_at_Onyx

Rumor has it that Workflows will have the ability to implement FOR WHILE loops ; however, workflows are not intended to be substitutes for ETL, so again, ideal state would be to be able to implement loop structures into ETL

With CTEs I can't see the need in SQL dataflows yet; but then we all know that CURSORs are not great for huge datasets which is one of the primary use cases for Adrenaline.

MySQL 5.6 does not support CTEs, they were however added to MySQL 8, https://www.mysqltutorial.org/mysql-cte/#:~:text=MySQL%20introduced%20the%20common%20table,the%20statements%20in%20this%20tutorial.

BethFerguson

100% agree with jaeW_at_Onyx. We need loop structures in ETL.