Help Understanding "Set Pipeline Variable" in Microsoft Fabric Pipelines

[HamidBee]

Hi all,

I’m working on a data pipeline in Microsoft Fabric and came across the "Set Pipeline Variable" activity, but I'm not quite clear on its purpose and usage. Could someone explain:

1. What exactly is a pipeline variable in Microsoft Fabric, and what is it typically used for?
2. At what stage or part of the pipeline process do you usually use this variable-setting activity?
3. What’s the difference between "Pipeline variable" and "Pipeline return value" in the "Variable type" option? How does each one function in the context of a pipeline?

Any insights or examples would be greatly appreciated! Thanks in advance.

[Expiscornovus · Accepted solution]

Hi @HamidBee 

1. To temporary store a value which you can easily reuse that value in other steps of your data pipeline and reference it via the variable. It is a typical concept of programming as well.

2. An example has been shared by Microsoft, you can for example is it in a counter in an for each loop to keep track of the number of loops: https://learn.microsoft.com/en-us/azure/data-factory/control-flow-set-variable-activity#incrementing...

3. The Pipeline return value can be used to interact with values of child pipelines, for reference see this section of the same document: 

https://learn.microsoft.com/en-us/azure/data-factory/control-flow-set-variable-activity#setting-a-pi...

https://learn.microsoft.com/en-us/azure/data-factory/tutorial-pipeline-return-value

Hopefully this helps a bit?