Passing values from parent pipeline to child pipeline in Azure Data Factory

Question

I'm pretty sure this is simple, but I can't seem to find this anywhere. I created a parameter in a parent pipeline (say the pipeline name is TestParent) in data factory:

This parent pipeline invokes a child pipeline. I want to reference this parameter in the child pipeline. What is the syntax to get the value of this parameter from the parent in the child?

Answer 1

OK I finally got this to work:

I completely removed the parameter from the parent pipeline. In the child pipeline (which is called HubMaster) we create a parameter called MasterBatchId:

In the parent pipeline I created an Execute pipeline node called EP_HubMaster that calls a child pipeline called HubMaster. In order to populate the child pipeline parameter MasterBatchId at run time, we need to edit the JSON of the parent pipeline to look like this:

{
"name": "TestParent",
"properties": {
    "activities": [
        {
            "name": "EP_HubMaster",
            "type": "ExecutePipeline",
            "typeProperties": {
                "pipeline": {
                    "referenceName": "HubMaster",
                    "type": "PipelineReference"
                },
                "parameters": {
                    "MasterBatchId": {
                        "value": "@pipeline().RunId",
                        "type": "Expression"
                    }
                }
            }
        }
    ],
    "folder": {
        "name": "Master"
    }
},
"type": "Microsoft.DataFactory/factories/pipelines"
}

You can see that we pass the @pipeline().RunId from the parent (which was the original intent) to the input parameter of MasterBatchId in the child pipeline.