How to extract an ID from a request's subsample or body in Jmeter & save it in CSV

Question

I am a beginner in Jmeter & trying to save an ID (like ID=1234567) in a HTTP request's response data using regex extractor & a 3rd party plugin called Dummy sampler with Filewriter but I am failing every time. Here is what it looks like:

/Registration/PaymentInformation?accountRegistrationId=372036

My objective is to save these accountRegistrationId in a CSV file & then use them in the following request as a parameter. The only part where I am stuck is capturing them & saving a file. After that I can manage. I have googled everywhere but cant find a solution. Please help me.

Answer 1

Following regex should work - (.*accountRegistrationId=)([0-9]+)(.*)
Use $2$ to retrieve the id.

JMeter regex reference