rails migration set default value code example
Example 1: rails migration add default value
change_column :users, :admin, :boolean, :default => false
Example 2: default value rails migration
t.integer :col_name, :default => 0
Example 3: rails migration update column default value
class MigrationName < ActiveRecord::Migration
def change
change_column :my_table, :my_column, :data_type, deafult: "value"
end
end