```ruby
class ConvertClosedToStateInMergeRequest < ActiveRecord::Migration
  def up
    MergeRequest.transaction do
      MergeRequest.where("closed = 1 AND merged = 1").update_all("state = 'merged'")
      MergeRequest.where("closed = 1 AND merged = 0").update_all("state = 'closed'")
      MergeRequest.where("closed = 0").update_all("state = 'opened'")
    end
  end

  def down
    MergeRequest.transaction do
      MergeRequest.where(state: :closed).update_all("closed = 1")
      MergeRequest.where(state: :merged).update_all("closed = 1, merged = 1")
    end
  end
end
```

Fix merge request migration for postgres
user
```ruby
class ConvertClosedToStateInMergeRequest < ActiveRecord::Migration
  def up
    MergeRequest.transaction do
      MergeRequest.where(closed: true, merged: true).update_all("state = 'merged'")
      MergeRequest.where(closed: true, merged: true).update_all("state = 'closed'")
      MergeRequest.where(closed: false).update_all("state = 'opened'")
    end
  end

  def down
    MergeRequest.transaction do
      MergeRequest.where(state: :closed).update_all(closed: true)
      MergeRequest.where(state: :merged).update_all(closed: true, merged: true)
    end
  end
end
```
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