Adding index :unique to a column in ruby on rails via generate migration

Question

I know that i can touch a migration and add

add_index :table_name, :column_name, :unique => true

But how is the right rails migration command to generate this?

rails g migration add_index_to_column_name :column_name, :unique => true

Is that right?

In my special example I have a table customers

  t.integer :customerID
  t.string :surname
  t.string :first_name
  t.string :phone

an i want to set the customerID to unique. Tried

rails g migration AddIndexToCustomers :customerID, :unique => true

But if i look to my migration file after this, it dont look right see this:

def change
    add_column :customers, :, :customerID,
    add_column :customers, :, :unique
    add_column :customers, :=, :string
  end

Any idea or suggestion?

Make sure not to use > true in your shell, or you'll create a true file via redirection. — Joe Atzberger
– Joe Atzberger, Commented Apr 27, 2017 at 0:31

notapatch · Accepted Answer · 2023-02-22 10:44:16Z

51

Starting from Rails 3.2 you able to use:

 rails g migration add_index_to_table_name column_name:type:uniq

 rails g scaffold Post title:string:index author:uniq price:decimal{7,2}

rails g migration add_index_to_customers customerID:integer:uniq

notapatch

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answered May 8, 2013 at 17:46

ck3g

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5 Comments

nope.. thats not working getting

def change     add_column :customerids, :customerID, :string     add_index :customerids, :customerID, :unique => true   end

tried rails g migration add_index_to_customers customerID:uniq but still creates the customerID as a string.

I've added more examples. You can pass type into migration.

yeah this helps... doing new question for this strange adding the datatype

It should be add_index_to_table_name not add_index_to_column_name.