Forum Discussion

ADORAISWAMY's avatar
ADORAISWAMY
New Contributor II
5 years ago

How to pass values to a child snap

I am a newbie to Snaplogic. I am developing a pipeline to copy data from Oracle tables to Snowflake using Snaplogic. I have created a parent pipeline and used “Pipeline Execute” to pass values to the child pipeline. I am having trouble understanding the concept of parameters, fields, $, _, _$. Everything is confusing me to the World’s end. I wish there was proper documentation for that.

The parent pipeline works perfectly and it displays data as expected. But I don’t know how to pass those values to the child pipeline. I have attached the pipelines here.

Please help me understand how the whole parameter concept works in Snaplogic.
Parent_2021_06_17.slp (6.6 KB)
Child_2021_06_17.slp (29.7 KB)

9 Replies

  • ptaylor's avatar
    ptaylor
    Employee
    5 years ago

    It looks like you’re very close. You just need to enable the expression button toggle (=) for the first and third expressions in the Mapper at the beginning of the Child pipeline:

    • ADORAISWAMY's avatar
      ADORAISWAMY
      New Contributor II
      5 years ago

      Hi Taylor.
      Thanks very much for replying. I made the change as you suggested but the output view in the child mapper doesn’t show the data as expected, even though it validates “green”. Is that expected or I am mistaken?


      • ptaylor's avatar
        ptaylor
        Employee
        5 years ago

        Hi. Unfortunately our UI doesn’t support a way to preview the output of snaps in a child pipeline when executed from the parent pipeline, so what you’re doing here is just executing the child by itself, correct? When you do that, the values of the pipeline parameters that the Mapper is referencing aren’t coming from the parent pipeline; they are just the default values of the pipeline parameters: