PostgreSQL database deployed on Heroku - possible view, add, delete rows in tables?

It looks like on Heroku should be psql command line tool available:

https://devcenter.heroku.com/articles/heroku-postgresql

https://devcenter.heroku.com/articles/heroku-postgresql#pg-psql

So it looks to me that after typing heroku pg:psql you should be connected to your database and be able to run any queries, see example in the last link.

Have you tried that?

Sure, indeed, thats it what I'm talking about. I can connect, I can see tables, I can see structure of each table, but I can not manipulate data in that tables (execute commands like SELECT, INSERT, DELETE) - all my SQL queries ignored. I have no idea, may be user on Heroku does not have needed roles for that, may be I'm wrong with syntax, support of Heroku does not help.

Nothing happens

Yes, I think I've tried all possible ways :) with semicolon, without it, etc.

So what I would do in your case,

first to try things out locally psql is installable app. And the web application you deployed should have POSTGRESQL database on your local machine. Try that out, execute commands if they work or not.

Second, when you get this done on local machine with local database, try to download database from your app from heroku:

 heroku pg:pull HEROKU_POSTGRESQL_MAGENTA mylocaldb --app sushi

Took this from here:

https://devcenter.heroku.com/articles/heroku-postgresql#pg-push-and-pg-pull

Also I would turn on logging, they say that can also help, somewhat like this:

heroku logs -p postgres -t

Took from here:

https://devcenter.heroku.com/articles/heroku-postgresql#logging

Did you turn on logging BTW ?