migration for column type decimal(10,2)

questions
1

Does anyone know how to create a migration to alter a column type to decimal(10,2)

2

What is the current schema for that column?

3

±------------±--------------±-----±----±--------±---------------+
| Field | Type | Null | Key | Default | Extra |
±------------±--------------±-----±----±--------±---------------+
| id | int | NO | PRI | NULL | auto_increment |
| category_id | int | YES | MUL | NULL | |
| name | varchar(255) | NO | | NULL | |
| body | text | NO | | NULL | |
| price | decimal(10,0) | NO | | NULL | |
| image_data | text | YES | | NULL | |
±------------±--------------±-----±----±--------±---------------+

When i try to alter it it changes the 2 to a 0

4

That should use set_column_type

ROM::SQL.migration do
  change do
    alter_table :orders do
      set_column_type :price, "decimal(10,2)"
    end
  end
end
5

Side note: this is not germane to your question, but I’ve spent a lot of time working on billing systems. I would not recommend using a plain decimal(10,2) for this, although that is better than a floating point.

Although PostgreSQL has monetary types, in my experience the best way to store money is an integer value that gets passed to the Money gem for localization.

Even if you’re not handling multiple currencies, it’s best to build it this way anyway.

6

Thank you. That should help.