CODEWITHSUNDEEP
ruby-on-railsmigration
zhouyu
zhouyu

Reputation: 287

Rails migration add_column with existing data

Using Rails and MYSQL. Existing table has a column called c1, I would like to add a column called c2 with data func(c1), func is the model method to deal with c1 data. How should I write the migration? Thanks

Upvotes: 0

Views: 122

Answers (1)

jimagic
jimagic

Reputation: 4065

  1. rails generate migration add_something_to_tablename something:string

  2. rake db:migrate

  3. Inside that model

add this line

before_save :do_something

add this method

private
  def do_something
    do something with c1
  end

Upvotes: 2

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