What is the proper way of adding a default boolean value that works in MySQL?

问题

I have ran my migrations on my production server and I am using MySQL, I get this error:

Mysql2::Error: Invalid default value for 'admin': ALTER TABLE users ADD admin tinyint(1) DEFAULT 'false'`

my migration looks like this:

class AddAdminToUsers < ActiveRecord::Migration
  def change
    add_column :users, :admin, :boolean, default: :false
  end
end

I understand the error is because "false" is not a proper value for a tinyint, this should be a 0 in this case. I thought default: :false was the right way to default a boolean to false.

How do I fix this so MySQL does not complain about the bad value?

回答1:

false is not a symbol I believe. Try this

add_column :users, :admin, :boolean, default: false

PS I am wrong. So you should set default: 0 :(. Or you can patch ActiveRecord::Migration so it will accept true|false

回答2:

This works in both PostgreSQL and MySQL:

add_column :users, :admin, :boolean, :default => false

I haven't tried this with Ruby 1.9.2's new hash syntax, but I don't think that will be an issue.

来源：https://stackoverflow.com/questions/9605573/what-is-the-proper-way-of-adding-a-default-boolean-value-that-works-in-mysql