Forum Discussion

XanderVR's avatar
XanderVR
New Contributor
2 months ago
Solved

Generate expression file from database query

For some data transformations I would like to use an expression file that is generated each night, instead of querying a SQL database everytime the pipeline is started. I already have data available...
expression_library
json
  • SpiroTaleski's avatar
    SpiroTaleski
    2 months ago

    XanderVR​ Achieving the desired output (without the getValue function) can be done using the reduce function. 

    First you need to group the records by $code, using Group By Fields snap. After that following expression can be used: 

    {[$groupBy.code]:$group.reduce((acc, curr) => acc.extend({[curr.source]: curr.target}), {})}

    BR,

    Spiro

Scott's avatar
Scott
Admin
2 months ago

Hi XanderVR - Can you take your question here and copy to SnapGPT, accessible in the Designer? It should generate a pipeline with expressions that get you what you are looking for.

 

  • XanderVR's avatar
    XanderVR
    New Contributor
    2 months ago

    I have tried that indeed, but it comes nowhere close to a solution.
    Every expression it generates in the mapper snaps are returning null values

    I managed to build a pipeline that completes this task, but since I am quite new to SnapLogic there might be better ways (ie. using less snaps) to achieve this result with better performance.