Ignore values when importing from CSV

Thanks for the reply. But I think you may want to re-read my post. If I wasn't clear, I'll try to re-articulate the problem. The initial webhook works fine until I run into the problem wherein several child records being updated in the projects table have the same location code. When the command encounters this scenario, it ceases to execute any portion of the command and returns an error:

<errtext>Trying to add a non-unique value to a field marked unique</errtext>
<errdetail>Your import data has duplicate values for the following unique fields</errdetail>


 I have to first figure out a way to parse the data before import. Ideally, without doing it in a separate app like excel. 

This is what I'm working on now. I found a few posts in the community that seem to offer some solution using JS. I'm not  well versed in js--it will take me a few days of trial and error to figure out his suggestion; so, I'm looking for a way to embed this in the webhook I designed (see above) if possible.