Chapter 10.1 - Foreign key constraints with SQLite? posted by Casey Smith @ Tue, 13 May 2008 00:44:16 -0000

Casey Smith — Tue, 13 May 2008 00:44:16 -0000

Awesome thanks Sam, I think it worked.

Chapter 10.1 - Foreign key constraints with SQLite? posted by Sam Ruby @ Tue, 13 May 2008 00:07:20 -0000

Sam Ruby — Tue, 13 May 2008 00:07:20 -0000

Try:

sqlite3 db/development.sqlite3 "drop table line_items;" 
rake db:migrate

Chapter 10.1 - Foreign key constraints with SQLite? posted by Casey Smith @ Mon, 12 May 2008 23:29:58 -0000

Casey Smith — Mon, 12 May 2008 23:29:58 -0000

Thanks Sam but I am still getting the same error message. I have given the error message again and the text from the file. I am loving Ruby and Rails. Thanks for writing the books and help us noobs out.

C:\rails\work\depot>rake db:migrate
(in C:/rails/work/depot)
5 CreateOrders: migrating ================================================
—create_table(:orders) -> 0.0940s
5 CreateOrders: migrated (0.0940s) =======================================

6 CreateLineItems: migrating =============================================
—create_table(:line_items)
rake aborted!
SQLite3::SQLException: table line_items already exists: CREATE TABLE line_items
(“id” INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, “product_id” integer NOT NULL, “order_id” integer NOT NULL, “quantity” integer NOT NULL, “total_price” decimal
(8,2) NOT NULL, “created_at” datetime DEFAULT NULL, “updated_at” datetime DEFAUL
T NULL)

File:

class CreateLineItems < ActiveRecord::Migration def self.up create_table :line_items do |t| t.integer :product_id, :null => false t.integer :order_id, :null => false t.integer :quantity, :null => false t.decimal :total_price, :null => false, :precision => 8, :scale => 2

t.timestamps
end

end
  def self.down
    drop_table :line_items
  end
end

Chapter 10.1 - Foreign key constraints with SQLite? posted by Sam Ruby @ Mon, 12 May 2008 20:47:59 -0000

Sam Ruby — Mon, 12 May 2008 20:47:59 -0000

For the moment, remove the two execute statements from db/migrate/006_create_line_items.rb. I have worked out a solution for SQLite3 that I will include in the next beta.

Chapter 10.1 - Foreign key constraints with SQLite? posted by Casey Smith @ Mon, 12 May 2008 18:09:47 -0000

Casey Smith — Mon, 12 May 2008 18:09:47 -0000

I have a problem when I run “rake db:migrate” after I have created and editied the models “order” and “line_item” on page 140 of Check out. I get:

C:\rails\work\depot>rake db:migrate
(in C:/rails/work/depot)
5 CreateOrders: migrating ================================================
—create_table(:orders) -> 0.0780s
5 CreateOrders: migrated (0.0780s) =======================================

(See full trace by running task with—trace)

Thanks for the help.

Chapter 10.1 - Foreign key constraints with SQLite? posted by Arthur Blair @ Fri, 09 May 2008 16:56:33 -0000

Arthur Blair — Fri, 09 May 2008 16:56:33 -0000

Indeed, the process of looking up foreign keys in sqlite myself scared me sufficiently to give up and ask here instead. I’ll see if I can get it to work myself, and look forward to the next beta.

Thanks for your rapid response.

Chapter 10.1 - Foreign key constraints with SQLite? posted by Sam Ruby @ Fri, 09 May 2008 16:21:17 -0000

Sam Ruby — Fri, 09 May 2008 16:21:17 -0000

My apologies, I’ll make sure that that will be fixed in the next beta.

Foreign keys are a bit more involved with sqlite3. I’m thinking of deferring this to late in chapter 16.

Chapter 10.1 - Foreign key constraints with SQLite? posted by Arthur Blair @ Fri, 09 May 2008 16:03:08 -0000

Arthur Blair — Fri, 09 May 2008 16:03:08 -0000

Page 141 uses MySQL statements to specify the foreign key constraints, which associate the rows of the line_items table with orders and products. However, using SQLite (as recommended earlier in the book) these statements give a syntax error:


...
-- create_table(:line_items)
   -> 0.0090s
-- execute("alter table line_items add constraint fk_line_item_products
             foreign key (product_id) references products(id)")
rake aborted!
SQLite3::SQLException: near "constraint": syntax error: alter table line_items add constraint fk_line_item_products
                 foreign key (product_id) references products(id)

Is there an alternative syntax that will work with SQLite? (Or have I done something wrong?)

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