I tried to create a new scaffold called Message and got this error message:
Another migration is already named create_messages
What can I do aside from changing the name of my model/controller/views (which I don't want to do)?
The reason this is occurring is I had a previous scaffold called Message that I changed to a different name (ran a migration to do this along with a search and replace for all filenames and variable/class names). I understand why I get this error message, just want to know how to move forward.
Quick fix is to rename old migration (create_messages) and try to generate scaffold again.
But recommendation is to have single create_messages migration so that it can be safely deleted by destroy scaffold command.
Update:
If already have Message model then no point in generating Message Scaffold, since scaffold does the same thing again with additional works like generating controller, routes etc.
If you already have a migration called create_messages you probably already have a Message model(Which means you can't have another named the same). If you have now decided you want to have a scaffold on the model to get the extra controller and view code use the following where name is the name of the column.
rails g scaffold Message name --skip
Related
I'm getting this error message when I run the above code generator: (I'm just a beginner)
invoke active_record
Another migration is already named create_posts.....
Use --force to remove the old migration file
What do I type into the terminal window to "use force"
You are getting the following error because you already have a migration named create_posts in your rails application.
invoke active_record Another migration is already named create_posts..... Use --force to remove the old migration file
So, what you need here is first remove the existing migration and then generate the scaffold.
rails d migration create_posts
rails generate scaffold post title:string body:text
Or
You could generate the scaffold using --force option
rails generate scaffold post title:string body:text --force
EDIT
As per your comment:
I did that and then a whole bunch of code appears with the lines of
code sating invoke...exist...identical.
It means that you already ran a scaffold once for Post successfully and you are trying to generate the scaffold again.
I am not sure why you are doing that BUT identical is not an error. Its just that Rails is telling you that you already have a particular file so I am not creating again.
You can reset your database if you don't care about losing your database with this :
b rake db:reset
This will re-reun all your migrations. But take note! Your migrations should be able to run from one end to the other. So if something is "not working" with the regular rake db:migrate, then you should resolve that issue is specifically.
Show me a more descriptive error, and I can tell you more.
You should add other migration in order to change your Post table as you want it to be.
Your could begin with rails g migration and see the help provided.
If you want to get away with it you can delete the migration that created the Post table (but I guess you would need to delete the DB)
After the first time you generate a scaffold, by default Rails will not overwrite the existing scaffold. This is to ensure that you don't accidentally destroy a lot of work.
If you're really sure you want to regenerate the scaffold and delete any changes you might have made to any of the generated files, try:
rails generate scaffold post title:string body:text --force
I was attempting to add a tagging model to my rails blog. But I accidentally generated a "Tags.rb" model as opposed to "Tag.rb", after reading the guide I realized that making "tag" plural was a mistake when it comes to model. I rolled back the migration using
rake db:rollback
and then
rails destroy model Tags.rb
and this was what i got back
invoke active_record
remove /home/migration/templates/create_table_migration.rb
remove app/models/tags.rb.rb
invoke test_unit
remove test/models/tags.rb_test.rb
remove test/fixtures/tags.rbs.yml
When I come back to the model folder though its still there.
Please help :)
Just give
rails destroy model Tag
Try using tags plural without the additional .rb, like
rails destroy model Tags
Hope this helps
You can manually delete the files, or just manually remove the "s"s.
try this
bundle exec rake db:rollback
and then delete your model as
rails destroy model <model_name>
now totaly deleted.
You can delete the migration files in migrate folder and model in your model folder and then you can again create new one which you wants.
you have to run that commands
rails g model tag
Then migrate database
rake db:migrate
First off, when generating a Rails model using rails generate model, don't add .rb to the end of the model name. Rails automatically does that so if you add .rb yourself then you end up with a model named Tag.rb.rb, which is invalid.
You're running the remove generator with "Tags.rb". Did you generate the model originally using rails generate model Tags.rb? If you did, then running rails destroy model Tags.rb will hopefully remove all the files, but since the model name is invalid, it might not work as expected (your use case is outside the intended use case of the generator). If you originally generated the model using rails generate model Tags, then running rails destroy model Tags should work.
If you originally invoked rails generate model Tags.rb, and running the remove command isn't working (which again, in understandable given that Tags.rb is an invalid name--would have been nice if the generator had originally prohibited you from generating a Tags.rb.rb file, but you can't have everything):
If you can afford to destroy your database and rerun all the migrations, the easy solution will be to manually remove the added files, destroy the database, and rerun all migrations. Then you can add the correct model using rails generate model Tag.
If you can't afford to destroy your database, then you'll need to manually find the problem migration in the migration's folder, run the down command on that migration, and then manually delete that migration file and all the other files.
I'm trying to generate a Post model in rails using the following code:
rails g model Post url:string, title: string
When I execute that line I get the following output:
invoke active_record
Another migration is already named create_posts: /Users/myname/Desktop/folder/my_project/db/migrate/20121212021831_create_posts.rb
It seems to be expressing a conflict as though the file already exists in my Model folder - which it does not.
Is this a naming problem? Any thoughts?
The conflicting migration would be in your db/migrate folder, not app/models.
Your two options are naming your new migration something else or removing the old migration. If you choose to remove the old migration, make sure to roll it back first before deleting it, so that your database schema is correct.
This problem can happen when you execute rails g model post for multiple times. You can resolve this issue by executing the rails destroy model post to remove last generated content.
I am new to Ruby on Rails . This might be a very foolish question.
I have created a migration using
rails generate migration Kapol name:string position:integer
rake db:migrate
Then using phpmyadmin i copied the database already present
I then opened up rails console
My question is can i use the method Kapol.find(1)??
because when i tried it using singular or plural it says
unitialized constant:Kapol
I know that there has to be a method but where to specify it?
You must generate a model in case to create a table for it, because the migration is usually used to modify existing tables.
It might be confusing that the model generator also creates migration file in your migrations folder. The only difference is that the model generator also generates initial code to create table, on the other hand, the migration generator creates only migration file without initial code.
rails generate model Kapol name:string position:integer
More information: http://guides.rubyonrails.org/getting_started.html#generating-a-model
If you're very new to Ruby on Rails, probably the best thing for you to do is create a scaffold, which gives you your migration file, your model file, your controller file, and various view files, test files, etc. etc., which all work well together. Then you can play with these and build up from there.
rails generate scaffold Kapol name:string position:integer
If you're happy with the migration that was automatically generated, then rake db:migrate and you're all set.
As Andrew says below, you can also just generate any of those files one at a time by replacing 'scaffold' with 'model', etc.
Your Kapol.find(1) is correct.
I created a Rails model (and controller) with a typo in the name. I renamed all of the files to the correct names, and then I rolled back the migration I used to create the table and changed it to recreate the table with the proper name.
Unfortunately, ActiveRecord still wants to use the old table name, even though it does not appear in any file in my project. I assume it has been cached somewhere but I have no idea where. There are no files in the application's tmp directory that look suspicious.
For the time being, I added a call to "set_table_name" to the model to get around the problem, but I'm really curious about where the old table name is stored and how to get rid of it.
Update: I went ahead and deleted the scaffold using "rails destroy scaffold". When I recreated it (without the typo), it recreated everything with the typo! I know the typo is cached somewhere but I have no idea where.
Rafe - Looks like it could be a bug in Rails. Perhaps you could submit a Rails pull request, or try adding to the config/initializers/inflections.rb file.
have you fixed the class name of your model? rails infers the table name from that
e.g. "class Userr" -> "userrs"
I generally spot typos quite quickly: the first time that the model is mentioned in the console or associations; the controller in the routes.
When I rails generate model urser I just rails destroy model urser and start again.
This just blasts the files away, but it's very convenient and in rails 3 works especially well to destroy every file created by the generator.
If I migrated before spotting the typo I'll let the migration be deleted by the destroy script, let the generate write a new one and then rake db:rollback. That way the urser_table from the previous migration is dropped and the user_table is created.
If there's a bit of code in the files, at that point is mostly in the model or controller itself. I just copy to clipboard the meat of the class before deleting the file and I paste it in the next one.
If there's a lot of code inside various models tests, controllers or helper files: I still use the same approach, but commit it to git before running destroy, so if you something it can always be checked back out.
OK, it turns out that with Rails 3 (and maybe other versions) if you try to generate a model named "Cafe" it will use the name "cave" instead. No idea why.
Here's an example. I duplicated this on different computers, too.
holloway:whatever rafeco$ rails g scaffold Cafe
invoke active_record
create db/migrate/20110412190231_create_caves.rb
create app/models/cafe.rb
invoke test_unit
create test/unit/cafe_test.rb
create test/fixtures/caves.yml
route resources :caves
invoke scaffold_controller
create app/controllers/caves_controller.rb
invoke erb
create app/views/caves
create app/views/caves/index.html.erb
create app/views/caves/edit.html.erb
create app/views/caves/show.html.erb
create app/views/caves/new.html.erb
create app/views/caves/_form.html.erb
invoke test_unit
create test/functional/caves_controller_test.rb
invoke helper
create app/helpers/caves_helper.rb
invoke test_unit
create test/unit/helpers/caves_helper_test.rb
invoke stylesheets
create public/stylesheets/scaffold.css