Add data to elastic search and join records

Hi, I have some questions I am new to elasticsearch. 1. I have a data file I would like to add it to elasticsearch how can I do it? Create a database first? The file is in csv. Do you have any guides for doing this or someone could explain it to me? I read the guide on the site but it didn't help me much. 2. I would like to combine records in a file using elasticsearch on the principle that the record already exists in the database, we join it with the previous one and add new data. It will be a long join because I have to check if all records match. I need to check compliance on 10 columns. So is it the same city, town, street, zip code, house number. My english is not very good, sorry for that!

Welcome!

You could read this blog post.
I also wrote a post which uses another strategy. See https://www.elastic.co/fr/blog/enriching-your-postal-addresses-with-the-elastic-stack-part-1

No 2:
You can build view from the database for that 10 fields that you need to ingest, if possible put the timestamp of the records.
Then use logstash with jdbc input for that database and the source is the view that you already built, build the template and put into the logstash output part.
Check the data in the elasticsearch, is there what you want, then build the dashboard or search apps.

Regards,
Fadjar Tandabawana