Composite index via command line migration, different behaviour in file

rubyonrails-talk
1

Hello everybody, I have a class like this:

class Foos < ActiveRecord::Migration   def self.up     create_table :foos,:id => false, do |t|       t.references :table1       t.references :table2       t.timestamps     end   end

  def self.down     drop_table :foos   end end

I would like to add a composite index on the 2 columns :table1 and :table2 but the command rails generate migration add_index(:foos, [:table1_id, :table2_id], :unique => true)

fails with the following output:   Missing type for attribute '='. Example: '=:string' where string is the type.

If I edit the up method of Foos like this:

  def self.up     create_table :foos,:id => false, do |t|       t.references :table1       t.references :table2       t.timestamps     end   add_index(:foos, [:table1_id, :table2_id], :unique => true)   end

then the index is successfully created. I can't understand why. I would like to create this composite index with a migration from command line.

Thanks

Federico

2

Hello everybody, I have a class like this:

class Foos < ActiveRecord::Migration def self.up    create_table :foos,:id => false, do |t|      t.references :table1      t.references :table2      t.timestamps    end end

def self.down    drop_table :foos end end

I would like to add a composite index on the 2 columns :table1 and :table2 but the command rails generate migration add_index(:foos, [:table1_id, :table2_id], :unique => true)

fails with the following output:    Missing type for attribute '='. Example: '=:string' where string is the type.

If I edit the up method of Foos like this:

def self.up    create_table :foos,:id => false, do |t|      t.references :table1      t.references :table2      t.timestamps    end    add_index(:foos, [:table1_id, :table2_id], :unique => true) end

then the index is successfully created. I can't understand why. I would like to create this composite index with a migration from command line.

As far as I know there just isn't a command line shortcut for creating such a migration - create a blank one with

rails g migration AddAnIndexToFoos

And add your call to add_index in there.

Fred

3

Thanks Fred, at least I'll stop bouncing my head against the wall trying to make my command work! I'll stick with your solution or mine.