So I read a few articles that I found in google how to make hstore make with Rails 4, and as it happens, it wasnt that easily as it was told so I decided to describe the steps that I had to take to make it work on UBUNTU machine...
The steps to activate and use Hstore:
1) You need to create a migration with something like this:
def change
enable_extension "hstore"
end
2) As it was for me, I had to install the thing called
postgresql-contrib
on my ubuntu machine, which I did with apt-get command. Perhaps you may need to add a version of your postgresql to the end of the packet name, like this:
postgresql-contrib-9.3
3) Now you can add migrations that add "hstore" fields to the tables, notice that these migrations should be following after the one that activates Hstore
4) Before u run the migrations, you might have to change to the root user of your DB and give the user that u use to access the db (most likely used in the database.yml file) an allowance to add this kind of columns, I did it with the following commands:
sudo -u postgres psql
(where postgres is the root user of the db )
and in the command line of the database write:
alter user [rails account name] with superuser;
5) Run the migrations
6) Change the user allowance back to the way it was with the following command:
alter user [rails account name] with nosuperuser;
That's it, now u should be able to use the hstore...
PS I am a bit of a newbie so perhaps I made some mistakes or something, but I hope its all fine :)