change an integer to bigint in ROR

Question

I need to change my table integers to BIGINT's I am using RoR and SQLLite.

How can I modify existing table fields from Int to BigInt through command line?

Answer 1

You can do that with a migration. Here's a link to the docs: http://edgeguides.rubyonrails.org/active_record_migrations.html

Basically, you need to run:

rails g migration change_your_column_to_bigint

and add this code to the migration new migration file:

def up
  execute <<-SQL
    ALTER TABLE ip_to_countries
    ALTER COLUMN your_column TYPE bigint USING your_column::bigint
  SQL
end

For the record, I stole this from here: How do I change a string column into a bigint?, but didn't mark it as duplicate because it involves converting a string column.

now I am getting this error

SQLite3::SQLException: near "ALTER": syntax error:     ALTER TABLE posts
    ALTER COLUMN mileage TYPE bigint USING mileage::bigint
C:/Sites/jeepjig/db/migrate/20150315145856_change_mileage_to_bigint.rb:3:in `change'
C:in `migrate'
ActiveRecord::StatementInvalid: SQLite3::SQLException: near "ALTER": syntax error:     ALTER TABL
    ALTER COLUMN mileage TYPE bigint USING mileage::bigint
C:/Sites/jeepjig/db/migrate/20150315145856_change_mileage_to_bigint.rb:3:in `change'
C:in `migrate'
SQLite3::SQLException: near "ALTER": syntax error
C:/Sites/jeepjig/db/migrate/20150315145856_change_mileage_to_bigint.rb:3:in `change'
C:in `migrate'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

after running this

class ChangeMileageToBigint < ActiveRecord::Migration
  def change
  execute <<-SQL
    ALTER TABLE posts
    ALTER COLUMN mileage TYPE bigint USING mileage::bigint
  SQL
end
end