question Re: JSON File Update in Support Questions

JSON File Update

ravi_sh_DS — Wed, 23 Sep 2020 05:45:19 GMT

Hi,

I have below JSON file with multiples image's details

{
"images": [{
"id": "C2934",
"ds_folder_id": "759838458734"
},
{
"id": "C8343",
"folder_id": "3942879137986"
}]
}.

I have id of the image and have to update the folder_id with some value.

For Example:

id is C8343 and the new folder_id is 2984584735

then I have to update folder_id of the JSON file with new one.

New JSON would be

{
"images": [{
"id": "C2934",
"ds_folder_id": "759838458734"
},
{
"id": "C8343",
"folder_id": "2984584735"
}]
}.

Please help me to perform above in NiFi.

Re: JSON File Update

stevenmatison — Wed, 23 Sep 2020 23:50:02 GMT

@ravi_sh_DS The solution you are looking for is UpdateRecord.

Here is a great article with full info:

https://community.cloudera.com/t5/Community-Articles/Update-the-Contents-of-FlowFile-by-using-UpdateRecord/ta-p/248267

If this answer resolves your issue or allows you to move forward, please choose to ACCEPT this solution and close this topic. If you have further dialogue on this topic please comment here or feel free to private message me. If you have new questions related to your Use Case please create separate topic and feel free to tag me in your post.

Thanks,

Steven

Re: JSON File Update

ravi_sh_DS — Thu, 24 Sep 2020 04:59:18 GMT

thanks ! @stevenmatison for the detailed explanation. 🙂

Re: JSON File Update

ravi_sh_DS — Thu, 24 Sep 2020 07:27:59 GMT

Hi @stevenmatison,

Thanks, but I have to make a judgemental update in JSON. As I explained in the example only id with a particular value will be updated.

Please assist.

Re: JSON File Update

stevenmatison — Thu, 24 Sep 2020 12:56:26 GMT

@ravi_sh_DS This gets a bit high level, so forgive me, as I am not sure how you know which ID to change and what to change it too. That said, your approach could be to use QueryRecord and find the match you want, then update that match with UpdateRecord. You can also split the json image array with SplitJson, then use UpdateRecord as suggested above. In either method depending on your Use Case when you split the records and process the splits separately you may need to rejoin them downstream.

Some older methods useful here are SplitJson, EvaluateJson, UpdateAttribute, AttributeToJson, but the Query Update Records are now preferred as it is possible to do things more dynamically.