Ruby On Rails data migration from sqlite3 to mysql regarding to many to many relations

Question

I have a sqlite3 database in my rails app which has a development.sqlite3 file. I want to convert the database to mysql.Here are the steps I take but still I have problems :

1.First I add and install gem 'seed_dump' to add the data into my seed.rb (By running rake db:seed:dump) because I really need to migrate my data .

2.Change the database.yml configuration to mysql setting.

development:
  adapter: mysql2
  encoding: utf8
  database: MyDB
  username: root
  password: ****
production:
  adapter: mysql2
  encoding: utf8
  database: MyDB
  username: root
  password: ****

3.Run rails db:create then rails db:schema:load.

4.Then loading the data from seed by running rake db:seed:dump

The problem is my many to many relations data (which has a table in db schema ) can't be imported in mysql from my seed.rb.

The thing I wanna know is that is there any other safe way to migrate my data from sqlite3 to mysql instead of writing them into seed.rb and then read them ?

ideally if you have a join table and you have your `seed.rb`, then the data from the join table should be written when saving your objects which have foreign keys to that table ... right? — Fabrizio Bertoglio, Apr 28 '18 at 09:42
@FabrizioBertoglio Yes and this gem creates a HABTM like thing in seed.rb which when I load seed it gets error! — Afsanefda, Apr 28 '18 at 09:46

score 0 · Accepted Answer · answered Apr 29 '18 at 06:15

As I was looking for another way to resolve the issue I've found what is declared here. I followed the steps facing to another error of mysql : Data is too long for column summary . To skip this error I turned off mysql strict mode like this in database.yml:

config/database.yml

development:
  adapter: mysql2
  encoding: utf8
  database: myDB
  username: root
  password: ****
  host: localhost
  strict: false


production:
  adapter: mysql2
  encoding: utf8
  database: myDB
  username: root
  password: **** 
  host: localhost
  strict: false

This solution is more clear than using gem 'seed_dump' which has problems with has and belongs to many relations!

Ruby On Rails data migration from sqlite3 to mysql regarding to many to many relations

1 Answers1