Questions tagged [ruby-on-rails]
Ruby on Rails is an open source full-stack web application framework written in Ruby. It follows the popular MVC framework model and is known for its "convention over configuration" approach to application development.
ruby-on-rails
338,329
questions
1583
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How can I rename a database column in a Ruby on Rails migration?
I wrongly named a column hased_password instead of hashed_password.
How do I update the database schema, using migration to rename this column?
- 16k
1216
votes
28
answers
1.2m
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Getting error: Peer authentication failed for user "postgres", when trying to get pgsql working with rails
I'm getting the error:
FATAL: Peer authentication failed for user "postgres"
when I try to make postgres work with Rails.
Here's my pg_hba.conf, my database.yml, and a dump of the full trace.
I ...
- 12.5k
1214
votes
15
answers
336k
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How to understand nil vs. empty vs. blank in Ruby
I find myself repeatedly looking for a clear definition of the differences of nil?, blank?, and empty? in Ruby on Rails. Here's the closest I've come:
blank? objects are false, empty, or a ...
- 13.6k
1128
votes
33
answers
574k
views
How do I get the current absolute URL in Ruby on Rails?
How can I get the current absolute URL in my Ruby on Rails view?
The request.request_uri only returns the relative URL.
- 86.7k
1063
votes
11
answers
230k
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1054
votes
20
answers
760k
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How can I rollback a specific migration?
I have the migration file db\migrate\20100905201547_create_blocks.rb.
How can I specifically rollback that migration file?
- 110k
992
votes
51
answers
437k
views
Can't find the 'libpq-fe.h header when trying to install pg gem
I am using the Ruby on Rails 3.1 pre version. I like to use PostgreSQL, but the problem is installing the pg gem. It gives me the following error:
$ gem install pg
Building native extensions. This ...
- 11.4k
835
votes
18
answers
578k
views
760
votes
20
answers
409k
views
How to "pretty" format JSON output
I would like my JSON output in Ruby on Rails to be "pretty" or nicely formatted.
Right now, I call to_json and my JSON is all on one line. At times this can be difficult to see if there is a ...
- 39.2k
736
votes
24
answers
518k
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How to drop columns using Rails migration
What's the syntax for dropping a database table column through a Rails migration?
- 9,728
727
votes
6
answers
441k
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Difference between rake db:migrate db:reset and db:schema:load
The difference between rake db:migrate and rake db:reset is pretty clear to me. The thing which I don't understand is how rake db:schema:load is different from the former two.
Just to be sure that I ...
- 14.8k
687
votes
18
answers
662k
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How to remove a key from Hash and get the remaining hash in Ruby/Rails?
To add a new pair to Hash I do:
{:a => 1, :b => 2}.merge!({:c => 3}) #=> {:a => 1, :b => 2, :c => 3}
Is there a similar way to delete a key from Hash ?
This works:
{:a => ...
- 170k
647
votes
6
answers
248k
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How to use concerns in Rails 4
The default Rails 4 project generator now creates the directory "concerns" under controllers and models. I have found some explanations about how to use routing concerns, but nothing about controllers ...
- 16k
646
votes
66
answers
607k
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Postgres could not connect to server
After I did brew update and brew upgrade, my postgres got some problem. I tried to uninstall postgres and install it again, but it didn't work as well.
This is the error message. (I also got this ...
- 6,623
638
votes
24
answers
458k
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Purge or recreate a Ruby on Rails database
I have a dev Ruby on Rails database full of data. I want to delete everything and rebuild the database. I'm thinking of using something like:
rake db:recreate
Is this possible?
- 110k