Rails Migration Decimal Column :default=> 0 re-setting MySQL precision to 0?

Question

I'm using Rails 3.0.3 (don't ask) and when I run a migration for table with decimal column and set :default => 0 it's re-setting the column's scale and precision to (10,0).

def self.up
 create_table :courses do |t|
  t.integer :user_id
  t.string :name
  t.decimal :distance, :precision => 5, :scale => 2, :default => 0
  t.text :notes

  t.timestamps
 end
end

When I remove the :default=>0 option from the migration the column's scaled and precision are correct: (5,2)

I tried running a change_column migration with only :default =>: 0 set, but the column's scale and precision were re-set to (10,0)

change_column :courses, :distance, :decimal, :default => 0.0

I know I can go into MySQL and correct the precision and scale of the column, but wondering if I'm doing something wrong or if this is a bug?

Google reveals no information so I think I'm doing something wrong.

Answer 1

Try this one: t.decimal :distance, :precision => 5, :scale => 2, :default => 0.00

Answer 2

I was also stuck on this one, and i cant find a solution to it. Eventually i had to go into mysql and change the required precision, scale and default value, i used this from here with a few modifications

mysql> ALTER TABLE question ADD (price INTEGER);
mysql> ALTER TABLE question DROP price;
mysql> ALTER TABLE question ADD (frig DECIMAL(5,2));
mysql> ALTER TABLE question CHANGE frig price DECIMAL(5,2);
mysql> ALTER TABLE question ALTER status SET DEFAULT '0';
mysql> ALTER TABLE question MODIFY price INTEGER;

Also try :default => 0.0 #note the 0.0 as the default value must be in the data type specified i.e. decimal

Hope it helps.