So my Mac went down and now trying to build my project on my new Mac. I need to know when running rake db:migrate does it look at the schema.rb file?
As I am getting
Mysql::Error: Table 'myproject_development.users' doesn't exist: SHOW FIELDS FROM `users`
Even when I run rake db:migrate:up VERSION=001 which has no reference to users I get the same error?
If it matters my migrations start like
001_...
002_...
003_...
20100222171241_...
The migration code generally doesn't look at the schema file. It looks at the names of all the migration files and the database table called schema_migrations, and determines which migrations haven't been run yet. (I believe it does dump the schema at the end of running migrations.) Either your missing a migration, or your schema_migrations table is out of sync with your database.
After making a backup, you can start to troubleshoot. Do you have a migration that creates the users table? If not, where did it go? If you have it, why isn't it running?
FYI The migrations that start with numbers (eg. 001) are older versions of migrations. Sometime around 2.2 or 2.3 the names of the migrations were changed to dates, which is what you are seeing in the later migrations.
There may be a problem with the way those first few migrations are named, and they are not being found (I can't remember the migration story when this naming scheme switched). And maybe it tracked the migrations differently back then so there may be some futzing to make it work with the more modern scheme. You can fairly safely rename them following the new scheme, using the datestamp of the file.
Hope this helps.
Related
Been able to make migrations (add columns etc) on my local machine with mysql.
But when trying to push these migrations to Heroku, they continue to fail.
The first table in my migration file gets tagged with:
Mysql2::Error: Table 'xxxxx' already exists
locally all my migrations showing as:
up 20171127214206 Add tags to business
but when running heroku run rake db:migrate:status
down 20171127214206 Add tags to business
i don't mind losing all the data at this point as i'm working in a development version on Heroku and will merge later with production
been working on this issue for over a day, so any and all advice appreciated.
according to this and many other sources, it appears you're better to use postgresql adapter with heroku. If you want to do that, you need to edit your database.yml similar to this
I know this one sounds kind of backwards! I've been working on a cloud-based case-management application, and was working on a support-ticketing feature. We have our development database (MySQL) that has all the same data as our production database (It's a very large app). Development is basically a "sandbox" environment, hence why the development db has all the same as the production db. This morning, I ran into a problem in my local development server for:
Migrations are pending; run 'bin/rake db:migrate RAILS_ENV=development' to resolve this issue.
Alright, did that, even though it didn't make any sense. It err'd out, because it was trying to create tables that already existed (I had already ran my migrations, the features were completed a day ago! And everything worked great).
The only thing that I did the moment before I got this message in my development server was uncomment an entirely-commented-out file to try and fix problems with TinyMCE (/config/tinymce.yml, text editor), followed by restarting my rails dev server. All this file was, was a bunch of defaults and plugins. When I saw the problem, I first commented them all back out. Still the same error. Proceeded with rake db: tasks.
Started looking for answers.. kept getting errors. Made a noob mistake, and ultimately did a
rake db:migrate:reset
which I knew would rebuild the schema at the cost of hosing the db. This failed.. But we do have the db in more than one place (since it's the same as production.) Also, just to try and bring all the tables back:
rake db:schema:load
....failed on one of the tables anyway with
ActiveRecord::StatementInvalid: Mysql2::Error: Specified key was too long; max key length is 767 bytes: CREATE UNIQUE INDEX `login` USING btree ON `users` (`login`, `intranet_id`)
..and all the tables are empty (as expected) that were successfully created. I'm by no means a database pro (I haven't dev'd very long). Am wondering, is there a way to copy the entire production database into the devel database? Tables, data, and all. Or any other suggestions? Really lost on this one.
You can use mysql_dump.
If you connect to the database everything is there - you just have to do a dump of the full database and then do the dump again into the production tables.
As you clearly see you can output from the database with ">" and you can import with the "<".
Using rails 3.2.8 ruby 1.9.3 p362.
There is something seriously amiss with my rails app. After so many db issues with an app, I STARTED FROM SCRATCH - read: rails new < new app name>
And started adding scaffolds and models. All in the past hour or so.
Then I tried to migrate a model called Product and I got the "Mysql2::Error: Table 'products' already exists" message when I ran rake db:migrate
Lo-and-behold my schema.rb file transformed itself into the mess of a file I had on my old app (on a different folder).
How can this happen? And how can I fix it?
Also, how often should I be pushing to git? I pushed once before building 2 new models and I already have a mess in my hands.
Help, please!
Did you clean up the old database for migrations from your older app / create a new database for the new app? Looks like it is the older database which is causing the issues.
You can go to your mysql prompt, and do a drop database database_name; and recreate an empty database using create database database_name.
I'm working with a project that is transitioning from sqlite to mysql. Unfortunately the schema of individual tables has changed somewhat and a wholesale import won't work. Are there any good tools or solutions to do this?
I'm using ruby on rails 3.0.10 currently. My best guess was going to be initiate a console session, use namespaced active record adapters to connect to both databases, and then copy all the items over in code.
(the original database is fairly small i.e. less than a few thousand rows per table)
What might be easiest is to export the Sqlite database in a format that can be loaded back in to MySQL directly, then create migrations that alter the schema as required, starting with the Sqlite structure and adjusting from there.
One tool you might try is yaml_db to dump the one database into fixture-style YAML files, and then load it back in on the other side.
Remember that your schema.rb file should be sufficiently database agnostic so as to allow you to rake db:create when switching your database.yml adapter definition.
You might want to create a separate environment for the previous structure by adding a new entry to database.yml and config/environments so you can switch back and forth without having to hack at a few different config files all the time.
I have created an app using a badly named database, all alterations to important data in the database have been done in fixtures so that I can just drop the database, recreate it and then rake migrate the database tables and fill them with the initial data from the fixtures.
I would like to change the name of my database now, so I updated the database.yml file to reflect another database name. I created the database in mysql and then tried to run the migration and fixtures.
Running the migration with trace shows that it is running commands to create tables etc. However once I am finished I get errors in my application saying that the tables don't exist in the new database.
I go into mysql and check the database and it is completely empty. I have tried wiping everything and running the migrations a few times but nothing changes. Is there something I am missing?
I don't know what commands you used to do the migration, but to migrate a production database (which I infer from the tag, "production-environment"), you have to do:
RAILS_ENV=production rake db:migrate
If that's not the answer, then please provide the command you used to perform the migration, which database you expected to be affected, and the relevant bits of database.yml.