Ruby Active Record Associations in Rails More Association Options A Migration for a Polymorphic Association

Muhammad sharifi
Muhammad sharifi
4,454 Points

anyone can tell me the correct command?

We need to be able to specify that a Part model belongs to either a Car or a Truck (which we will refer to as "vehicles"). Assume that cars and parts tables already exist. Here at the command line, generate a migration that will add vehicle_id and vehicle_type columns to the parts table.

1 Answer

Steve Hunter
MOD
Steve Hunter
Treehouse Moderator 56,146 Points

Hi there,

For this you you need to use the rails generate command to create a migration. To tell the framework which table to modify, you can use title case to say, for example, AddColumnsToExample where Example is the table you are adding the columns to.

Next, specify the name of the column and the data type, separated by a colon. You're given these in the question. There's vehicle_id which we can assume is an integer and vehicle_type which I called a string.

Tying all that together and you should get through the challenge

Steve.