CODEWITHSUNDEEP
ruby-on-rails-3
Nando
Nando

Reputation: 747

No autoincrement primary key ID in Rails Migration

In Rails Migration File is possible to create a column ID primary_key no auto_increment?

Upvotes: 3

Views: 3240

Answers (2)

Toni Schilling
Toni Schilling

Reputation: 117

Seems, that Yuki´s answer got too old? It didn´t work for me. But the following worked:

class CreateNoAutoincrement < ActiveRecord::Migration[4.2]
  def up
    create_table( :my_table, :id => false ) {|t|
      t.integer :id,    null: false ;
      t.string  :token, null: false ;
    }
    add_index :my_table, :id,    unique: true ;
    add_index :my_table, :token, unique: true ;
  end
  def down
    drop_table :my_table ;
  end
end

On MariaDB the table looks like this:

MariaDB [foo_devel]> describe my_table ;
+-------+--------------+------+-----+---------+-------+
| Field | Type         | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| id    | int(11)      | NO   | PRI | NULL    |       |
| token | varchar(255) | NO   | UNI | NULL    |       |
+-------+--------------+------+-----+---------+-------+
2 rows in set (0.001 sec)

It´s nice, that I still get a primary key, not just two Unique Indexes (probably because the column name is 'id')

Upvotes: 1

Yuki Matsukura
Yuki Matsukura

Reputation: 456

I succeeded dropping auto_increment by running following change_column method.

class DropAutoIncrement < ActiveRecord::Migration
  def change
    change_column :my_table, :id, :integer
  end
end

I used activerecord 4.0.2.

Upvotes: 2

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