I typed this into terminal:
rails generate migration CreateAddress
and instead of creating a new migration file, it created the entirety of a naked rails app.
What is wrong here?
The generate script is a Ruby script, so you should just call it with ruby.
Also, you usually want to call that script from the top level of your app, so:
$ ruby script/generate migration CreateAddress
The reason you have your issue is because executing rails simply creates a naked Rails app in your current directory with the first argument as its name. In this case, that's obviously "generate".
Related
I used to be able to type rails generate or rails generate model to
get help information for different rails command lines, for some
unknown reason, now if I type rails generate or rails generate model,
it always show me the help message for rails new, what is going on?
This normally happens if you are not in a rails path, so make sure your curfrent terminal / cmd is in a directory with a rails app you can change dirfectory with cd "/putdirectoryhere"
I am following the Rails Tutorial. It is starting to generate a scaffold. I just don't know for sure where to pit it. In a subdirectory or right at the root. My hunch is the root. i.e. JimJones$ not JimJones$/work/newapp. The apps can keep[ changing so I would imagine I would install the scaffold at the root. Any help would be greatly appreciated. Thanks, Chris
Your hunch is wrong, you should be in your /newapp directory, assuming that's the name of your app.
If you're not sure where you're at, enter pwd at the command line, and this will
print out your current location. If it ends in /newapp, you're all good.
rails generate scaffold myscaffold creates a set of MVC scaffolds called myscaffold(s), INSIDE your current app. In fact, You shouldn't be able to run rails generate scaffold unless you are inside a rails project.
Scaffolding is specific to Rails applications. First create a new Rails application using rails new appname command. Then move to the appname directory.
Then use scaffolding
rails generate scaffold test
The above command will generate a set of model, database migration for that model, controller, views, and test suites for the resource test
More info on scaffolding : http://guides.rubyonrails.org/command_line.html
You need to be in the rails app directory to use scaffold and the code generated by scaffold will be put in appropriate locations in your rails app directory e.g. model in models directory controller in controllers
strange problem with rails migration.
I have 2 migrations in my app
I run rake db:migrate
Only one migration executed. No matter how many time I tried, the second migration was ignored
I also tried to run the specific migration by specifying a version number, but no luck
Use rails 4.1
The first migration generated by
rails g scaffold User .......
The second migration generated by devise plugin
rails g devise user ........
The migration file generated is without extension .rb.
It was an issue that was already reported in Devise. It was resolved in Devise version 3.2.3. Read the issue Generated migration filename missing extension #2971
Second file needs the .rb extension?
When I read Rails book, each time they create a new database, always follow a db:migrate.
rails generate scaffold school
rake db:migrate
In console view, I see at first line, Rails create some files, no problem. but in second line, I see that Rails isn't really change anything. I have view some files that Rails nearly create and see no change too.
So, what the purpose of line 2, please tell me.
Thanks :)
The rake migrates the changes into your database. It is which acttually changes the database schema to match your previously generated scaffolded model.
Without it, you wouldn't have a table to write your objects into. Or in case of changed model, the table could differ from your model, leading to error.
When you generate a model (or scaffold one) a migration file is created in your db/migration directory. It is a pure text file, you can create such manually, if you want. This is the tool for the iterative development in rails regarding the database. Each migration adds some change to the system. When you run rake db:migrate your database is updated by the given migrations. This is a handy tool in case of distributed development, when one programmer can check out the code from the repository, and can run the migrations on his own development database.
db:migrate, is the command that tells rails to update the database with new changes. Think of it as this way
when u say rails generate scaffold rails will generate files like a model, controller etc.. and it create a file under db/migrate which has the sql script to update the database.
Ex: if you run rails generate scaffold User name:string, then you will need a table called users in the database with the column 'name', that sql script will generated under db/migrate folder
with db:migrate, command, you are telling rails to migrate new sql scripts to the database, in the above case, it will creates the 'users' table
if you run rake -T, from your rails application root, you could see all the rake tasks
HTH :)
I have a RoR project on my Windows 7 PC.
I want to create some Ruby code that I can execute from the cmd.exe command line that manipulates the development database (via database.yml) of the project. (I don't want to have to run my utility code via a web page.)
What is the best way to go about pulling this off? (I'm a newbie.)
I can't put the code in the test/ directory because that executes against the test database.
I tried just creating a utility.rb file under app/ but when I run it I get this:
utility.rb:5: uninitialized constant ActiveRecord (NameError)
My standalone file obviously doesn't know about the rest of the rails framework.
Any suggestions?
Rails comes with a utility to do exactly this. Instead of using ruby filename, use script/runner filename (from within the top-level directory for the Rails project), which will automatically load up your Rails environment before running the script.
However, if what you're trying to do is manipulate the database, the right answer is probably to create a migration. Most people assume that migrations are only for changing the structure of your database (adding or removing columns or tables) but they can also be a great way to add seed data or manipulate all the data in the database.
You can write your own rake task which depends on :environment and pass RAILS_ENV=development when executing it.
Nice screencast about it: screencast