Specify custom primary key in migration

Question

I have a data structure:

  t.integer :userID
  t.string :apikey
  t.integer :characterID

The userID should be the primary key (name is not important, it can default to :id). However, I don't want it to be auto incrementing or anything else, just take the value provided and write it into the database.

How do I have to adjust the migration and the model to achieve what I want?

score 22 · Accepted Answer · edited Apr 29 '15 at 16:04

22

 create_table(:my_table, :primary_key => 'userID') do |t|
   # Primary key column will be created automatically
   # Do not create here
   # t.column :userID, :integer, :null => false
   ...
 end

Or

create_table :my_table, {:id => false} do |t|
  t.integer :userID
  t.string :apikey
  t.integer :characterID
  t.timestamps
 end
 execute "ALTER TABLE my_table ADD PRIMARY KEY (userID);"

And don't forget to put this line somewhere in model:

 set_primary_key :userID

edited Apr 29 '15 at 16:04

Wen

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answered Jun 19 '11 at 12:04

Mohit Jain

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In your first example, shouldn't it be `:integer`? `userID` still is an `integer`, not varchar. – Femaref Jun 19 '11 at 12:15
1

@MohitJain: is it necessary to put the "set_primary_key" using both methods you suggested, or the "set_primary_key" is meant to be used on the second method only? – Eduardo Dec 06 '12 at 18:45
1

@Eduardo In both the cases. – Mohit Jain Dec 07 '12 at 05:36

score 0 · Answer 2 · answered Jun 19 '11 at 13:04

0

Instead of circumventing the ActiveRecord model, I made userID a normal column and used

validates_uniqueness_of :userID, :message => "userID needs to be unique"

on the model to validate it.

answered Jun 19 '11 at 13:04

Femaref

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Did you add an index? If you are going to search using the `userId` that is essential. – nathanvda Jun 19 '11 at 19:31

Specify custom primary key in migration

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