hi im currently learning rails, and following a tutorial. the instructions were to edit the migration file after i've created the app, then running rake db:migrate, then rake db:create.
i've edited the migration file to this:
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :username
t.string :email
t.string :encrypted_password
t.string :salt
t.timestamps
end
end
end
then when i've run 'rake db:migrate' i got an error
Mysql2::Error: Table 'users' already exists: CREATE TABLE `users` ...
after i'm supposed to run 'rake db:create', then im getting this
user_auth_development already exists
user_auth_test already exists
You run rake db:create once and only once, and you run it first. Then you run rake db:migrate every time you add/change a migration. You've either already run this migration, or you are pointing at a database that already exists and already contains a table named users. My guess is that you ran the migration once already, in which case you're probably good to go. If you want to nuke the DB and start over, do rake db:drop db:create db:migrate.
We can simply give, it will do all the rake task which is require for database creation and migration
rake db:setup
For Rails 5 and 6, the command is:
rails setup
This will "create the database, load the schema, and initialize it with the seed data" (docs).
For rails 6 & above, you can give this command to create a database, migrate all the migration files, and seed the data into the database:
rails db:prepare
Related
I'm new to RoR. The following line executed normally:
bundle exec rake db:migrate
Output showed that it is migrated. development.sqlite3 and production.sqlite3 were created but empty, although schema.rb was written properly. The users table was successfully created, but without any records. Also I executed:
bundle exec rake db:test:prepare
test.sqlite3 is created and also written properly. This is the content of the file inside the migration file:
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :name
t.string :email
t.timestamps
end
end
end
Kindly help me solve the problem. Let me know if any other details need to be specified.
So bundle exec rake db:test:prepare probably sets your environment to test.
That would be the reason why you'll end up with a working test database.
If you want to have the data in the development database, you need to set the environment to development.
Try RACK_ENV=development bundle exec rake db:test:prepare.
Although the cleaner solution is to create a seed file. See: http://edgeguides.rubyonrails.org/active_record_migrations.html#migrations-and-seed-data
I've been trying to get the Paperclip gem working. The problem that I was initially running into was that pictures were getting uploaded but not displaying. I then messed around with the database by doing a rake db:rollback to try and fix the error. Now I can't rake db:migrate again because of this error
SQLite3::SQLException: duplicate column name: image_file_name: ALTER TABLE "posts" ADD "image_file_name" varchar
I've personally went into the migration folder and deleted the file to try and generate a migration again. I've been trying to do rails generate paperclip post image and it does create a migration file, but I'm unable to rake db:migrate.
Any suggestions?
Thanks!
Deleting a migration file doesn't really rollback the change it made in your database. Your best bet is to:
Don't delete the migration but comment out the content of the migration class, and run rake db:migrate,
Let's say I have this as my migration file
class AddEmailSentToNeeds < ActiveRecord::Migration
def change
add_column :needs, :email_sent, :boolean ,default: false
end
end
Just comment out the method but leave the class, so it would be:
class AddEmailSentToNeeds < ActiveRecord::Migration
# def change
# add_column :needs, :email_sent, :boolean ,default: false
# end
end
This is just a hacky way to tell rails to skip this migration.
OR
start from the start so go do, rake db:drop, rake db:create, and rake db:migrate
I'm at the very beginning stages of learning rails using heroku as deployment tool. I ran into a bit of problem today, which is now fixed, but I was wondering if there's a proper/better way to do what I did.
My problem was as follows: I wrote a migration file that created a table with some indices (using add_index). The code would look like this:
class DeviseCreateUsers < ActiveRecord::Migration
def change
create_table(:users) do |t|
t.string :username
...
end
add_index :users, :username, :unique => true
end
def self.down
drop_table(:users)
remove_index :users, :username
end
end
heroku run rake db:migrate ran fine but heroku run rake db:rollback failed because (I assume) remove_index was trying to delete an index from a column that had already been erased.
So I then added a self.down method to my migration file (removing the indices before dropping the table). Afterwards, heroku run rake db:migrate didn't do anything, and heroku run rake db:rollback is stuck at the same error as before. Resetting the database or dropping the table didn't work either. I ended up removing the add_index lines in my migration before the rollback finally works.
... and unfortunately I no longer have any idea why db:rollback failed. The error message was 'index_users_on_username' on table 'users' does not exist', so my guess is that I did something stupid like modifying the database or modified the migration file before doing a rollback. Or could it be because I am mixing change and down method in the same migration file?
Anyway, my main question is, if a db:rollback fails, what then?
Some options in my head:
Fix the migration file until the rollback works
Fix the database manually until the rollback works
Fix the database manually and ignore the migration completely (dunno how to do this)
this)
???
am currently working on a rails project. When i tried to start rails server its throwing the following error:
=> Booting WEBrick
=> Rails 3.1.3 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/var/lib/gems/1.9.1/gems/activerecord-3.1.3/lib/active_record/connection_adapters
/sqlite_adapter.rb:439:in `table_structure': Could not find table 'dbrick'
(ActiveRecord::StatementInvalid)
My table name is 'dbrick'. I also Tried to rake db:drop and rake db:mirgrate. While migrating its throwing the following error:
rake aborted!
Could not find table 'dbrick'
Tasks: TOP => db:migrate => environment
(See full trace by running task with --trace)
This is my migrate file:
class CreateDbricks < ActiveRecord::Migration
def self.up
create_table :dbricks do |t|
t.text :description
t.string :video
t.string :video_html
t.string :image_id
t.string :option_id
t.boolean :choice
t.string :reach
t.integer :category_id
t.string :user_id
t.datetime :deleted_at
t.timestamps
end
end
def self.down
drop_table :dbricks
end
end
It will be so much help full if any one help me out of this.
Thanks in advance.
I would try :
rake db:schema:load
To load your schema ( to which I believe its finding the error against your DB ).
If that fails, I would manually find the migration that creates your dbrick, locate the name of the file and copy and paste the number in the filename to produce this :
rake db:migrate:down VERSION=123412341234 # <-- where the number is the number you pasted
Look for errors. Occasionally one thing exists already, or doesn't exist already and prevents the migration from running all the way, and consequentially that would be the source of your error. If it goes successfully then rake it back up :
rake db:migrate:up VERSION=123412341234 # <-- where the number is the number you pasted
If it doesn't go successfully, then you'll have to put on your miner's helmet, and get your hands dirty with :
rails dbconsole
Which will take you into your database and you'll have to manually delete whatever table/column is preventing the migration from occurring. Once that is fixed, exit out and rake db:migrate:up!
Have you migrated your database? rake db:migrate
If you have, drop your database (this deletes all data, so be careful - do it if you do not care about losing data in your db)
rake db:drop
This will clear out your database, and your schema. Then
rake db:migrate
This will re-migrate your schema.
I am new to RoR and I keep getting this error message:
$ rake db:migrate
== CreateUsers: migrating ====================================================
-- create_table(:users)
rake aborted!
An error has occurred, this and all later migrations canceled:
SQLite3::SQLException: table "users" already exists: CREATE TABLE "users" ("id"
INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "name" varchar(255), "email" varchar
(255), "created_at" datetime, "updated_at" datetime)
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
I've been searching for a solution for 3 days, but I cannot seem to find anything that works for me.
Thank you in advance for your help :)
PS - I am running off Windows.
Not sure if you are following Michael Hartl's tutorial on RoR.
But someone has said there's a problem in the steps of the tutorial http://archive.railsforum.com/viewtopic.php?id=44944
rake db:drop:all <---------- will wipe everything then run rake db:migrate again should fix the problem.
Good Luck
table "users" already exists seems to be the problem. Have you tried to manually remove the table from your database with some SQLITE admin tool?
Or you can include a remove table in your migration script (should be called create_users.rb inside your db/migrate folder). Inside def up insert drop_table :users :
def up
drop_table :users
create_table :users do |t|
t.string :name
#...
t.timestamps
end
Oh and I remember from my RoR time that the table name "Users" can cause problems later on. Might be this is related.
Because the table already exists, you need to delete/remove it before executing the migration.
Easy, GUI way to do this is with the SQLite Database Browser (http://sourceforge.net/projects/sqlitebrowser/).
Click the button with the Table-X icon. Choose User Table click Delete.
Then run rake db:migrate
Bada boom bada bing
I had the same problem and after several hours I finally found the solution
I’ve put
def self.up
create_table :users do |t|
def down
drop_down :users
end
end
Then make rake db:migrate and Magic !!!!
I had a similar problem, then i did
=> rake db:drop
=> rake db:create
=> rake db:migrate
worked perfectly.
But if it doesn't work we could try something like
ActiveRecord::Migration.drop_table('users')
ActiveRecord::Migration.create_table('users')