CODEWITHSUNDEEP
ruby-on-railspostgresqlrails-activerecordrails-migrations
Jake
Jake

Reputation: 1370

Rails error: Index name '...' on table '...' already exists while running rails db:migrate

So I'm working with a colleague who added some additional migration files and per normal procedure once I pulled their version I ran rails db:migrate. I end up getting the following errors:

 Index name 'index_authorizations_on_user_id' on table 'authorizations' already exists

 ArgumentError: Index name 'index_authorizations_on_user_id' on table 'authorizations' already exists

So I went and checked the schema and the table is already present. So why is it failing? Typically in the past it only generates new table entries/updates when doing a migration so why isn't it just ignoring it?

I've tried doing a rollback and get: This migration uses remove_columns, which is not automatically reversible.

I've tried doing bin/rails db:migrate RAILS_ENV=development and I get the same errors.

I've done a db:reset, db:drop, and it all comes back to an issue with pending migrations that I cannot get to run. What am I doing wrong?

They added the following migration: 20171024074328_create_authorizations.rb

 class CreateAuthorizations < ActiveRecord::Migration[5.1]
  def change
    create_table :authorizations do |t|
      t.string :provider
      t.string :uid
      t.references :user, foreign_key: true

      t.timestamps

      add_index :authorizations, :user_id
      add_index :authorizations, [:provider, :uid], unique: true
    end
  end

end

Upvotes: 8

Views: 9964

Answers (4)

user22029208
user22029208

Reputation:

The solution for me was to drop the indexed column that had a unique constraint and then reindex

Upvotes: 0

Giggs
Giggs

Reputation: 1039

Check if it's a table or a changed table, most times you need to drop the table or delete the column then run the migration again and it'll be good to go

Upvotes: 0

Jake
Jake

Reputation: 1370

So the only thing that I've found that "worked" was to actually delete the migration files then run rails db:migrate. Didn't catch on anything, no errors.

Not a fan of the fact that this worked.

Upvotes: 0

mu is too short
mu is too short

Reputation: 434585

This:

t.references :user, foreign_key: true

adds an index on authorizations.user_id for you. If you check the references documentation it will point you at add_reference and that says:

:index
Add an appropriate index. Defaults to true. [...]

So index: true is the default when you call t.references :user and that creates the same index that add_index :authorizations, :user_id creates.

Upvotes: 8

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