rails generate migration AddRetweetsCountToTweet retweets_count:integer
Ok I use above line to create migration file that automatically generates code in the generated file to add a column to a model Tweet with datatype integer. Now I want to add default value to the added column while generating the migration file. Is that possible? I googled it but couldn't find. Guys need help.
This question is related to
ruby-on-rails
migration
You would have to first create your migration for the model basics then you create another migration to modify your previous using the change_column ...
def change
change_column :widgets, :colour, :string, default: 'red'
end
I tried t.boolean :active, :default => 1 in migration file for creating entire table. After ran that migration when i checked in db it made as null. Even though i told default as "1". After that slightly i changed migration file like this then it worked for me for setting default value on create table migration file.
t.boolean :active, :null => false,:default =>1. Worked for me.
My Rails framework version is 4.0.0
Yes, I couldn't see how to use 'default' in the migration generator command either but was able to specify a default value for a new string column as follows by amending the generated migration file before applying "rake db:migrate":
class AddColumnToWidgets < ActiveRecord::Migration
def change
add_column :widgets, :colour, :string, default: 'red'
end
end
This adds a new column called 'colour' to my 'Widget' model and sets the default 'colour' of new widgets to 'red'.
Source: Stackoverflow.com