Problems setting a custom primary key in a Rails 4 migration
Solution 1
Take a look at this answer. Try to execute "ALTER TABLE shareholders ADD PRIMARY KEY (uid);"
without specifying primary_key parameter in create_table block.
I suggest to write your migration like this (so you could rollback normally):
class CreateShareholders < ActiveRecord::Migration
def up
create_table :shareholders, id: false do |t|
t.integer :uid, limit: 8
t.string :name
t.integer :shares
t.timestamps
end
execute "ALTER TABLE shareholders ADD PRIMARY KEY (uid);"
end
def down
drop_table :shareholders
end
end
UPD: There is natural way (found here), but only with int4 type:
class CreateShareholders < ActiveRecord::Migration
def change
create_table :shareholders, id: false do |t|
t.primary_key :uid
t.string :name
t.integer :shares
t.timestamps
end
end
end
Solution 2
In my environment(activerecord 3.2.19 and postgres 9.3.1),
:id => true, :primary_key => "columname"
creates a primary key successfully but instead of specifying ":limit => 8" the column' type is int4!
create_table :m_check_pattern, :primary_key => "checkpatternid" do |t|
t.integer :checkpatternid, :limit => 8, :null => false
end
Sorry for the incomplete info.
Alexander Popov
Updated on June 17, 2022Comments
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Alexander Popov almost 2 years
I use postgresql 9.3, Ruby 2.0, Rails 4.0.0.
After reading numerous questions on SO regarding setting the Primary key on a table, I generated and added the following migration:
class CreateShareholders < ActiveRecord::Migration def change create_table :shareholders, { id: false, primary_key: :uid } do |t| t.integer :uid, limit: 8 t.string :name t.integer :shares t.timestamps end end end
I also added
self.primary_key = "uid"
to my model.The migration runs successfully, but when I connect to the DB using pgAdmin III I see that the uid column is not set as primary key. What am I missing?
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Alexander Popov over 10 yearsThat's exactly what I missed to write in the question. While I was able to do this, I want to know if there is a way to achieve this in "natural" way, that is without executing direct sql queries. Nevertheless, since there aren't any other suggestions I accept this as a best answer. :)
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Alexander Popov over 10 yearsBut what is the type of the primary key in this case? I need it to be bigint.
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peresleguine over 10 yearsSorry, missed it. It is int4. Yet this way is not for us.
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peresleguine over 10 yearsSince
primary_key
method accepts only one argument, I see no other way but to use plain sql for bigint. -
bkdir over 6 yearsBy default Primary keys in Rails 5.1 are bigint: github.com/rails/rails/pull/26266
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ortonomy almost 2 yearsrarrrrr, I can't upvote this enough. We're at Rails 7 and it still no reference in it's docs if you don't want to use
id
as the primary key column on a table