Rake migrate- problems

I am very new to RoR and mySQL, so please excuse my ignorance.

I am having a problem creating a mySQL table via migration. I am using
O’Reilly’s “Ruby on Rails- Up and Running” book as a guide and I am
stuck on page 39. The author is inserting rows into a table called
‘slideshows’, ‘slides’ and ‘photos’. However I am unable to insert any
data into row one of the photos table because I already have done so.
So I deleted the whole table and migrated to VERSION=0 and then migrated
back up in hoping that the ‘photos’ table would have been recreated.
However it hasn’t, but the ‘slideshows’ and ‘slides’ tables have been
recreated in this migration process. Why hasn’t ‘photos’ table been
recreated?

Any suggestions?

Also you can view all of the pages I gone thru in the link below. Just
click on the book with the ibex (wild goat) on it.
http://books.google.com/books?q=ruby+on+rails&btnG=Search+Books&as_brr=0

Thanks for your time!

Hi

On page 37 and 38 I can see the migrations for slideshow and slides
tables.
I dont see a migration for photos…do you have a migration for the
photos
table?

If so, can you paste the code so we can have a look. If you only have 3
migrations, paste al 3.

Ivor

Below are the three files that create the 3 tables.
So I will do the following command;

rake migrate VERSION=0;

…I will see it drop the other two tables (slideshow and slides). Kept
in mind I manually deleted ‘photos’ so I am not excepting to see
‘photos’ being dropped at this point.

But when I migrate back up by doing this;

rake migrate VERSION=3;

…I ONLY see the other two tables being created. I do check this in
mySQL by using the ‘show tables’ command.

<!—001_create_photos.rb–>
class CreatePhotos < ActiveRecord::Migration
def self.up
create_table “photos” do |photo|
photo.column “filename”, :string
end
end

def self.down
drop_table “photos”
end
end

<!—002_create_slideshows.rb–>
class CreateSlideshows < ActiveRecord::Migration
def self.up
create_table “slideshows” do |t|
t.column “name”, :string
t.column “created_at”, :datetime
end
end

def self.down
drop_table “slideshows”
end
end

<!—003_create_slides.rb–>
class CreateSlides < ActiveRecord::Migration
def self.up
create_table “slides” do |t|
t.column “position”, :integer
t.column “photo_id”, :integer
t.column “slideshow_id”, :integer
end
end

def self.down
drop_table “slides”
end

The one difference I note is that you are using

create_table "photos" do |photo|
  photo.column "filename", :string
end

where in the other tables |t| is used. Is it possible that photo is
used somewhere else?

What’s Rails version are you using??

2007/2/24, __ myIP [email protected]:

– drop_table(“slides”)
rake aborted!


Weverton G. de Morais
Tecnólogo em Redes de Comunicação
Desenvolvedor Delphi

Below is part of the output I got when I did “gem list --local”. I am
using this version of rails because the authors are also using this
version for the book.

rails (1.1.6, 0.12.1)
Web-application framework with template engine, control-flow layer,
and ORM.

rake (0.7.1)
Ruby based make-like utility.

Thanks Joe for your feedback, however that didn’t solve the problem.
Below are my traces when I do the following migrating. So it seems that
it attempts to drop the table ‘photos’ but it throws an error. And when
I attempt to create it by migrating back up, it fails silently.

<!—MIGRATE BACK-DOWN -->

== CreateSlides: reverting ========================
– drop_table(“slides”)
-> 0.1200s
== CreateSlides: reverted (0.1200s) =================

== CreateSlideshows: reverting ====================
– drop_table(“slideshows”)
-> 0.0400s
== CreateSlideshows: reverted (0.0400s) =============

== CreatePhotos: reverting =======================
– drop_table(“photos”)
rake aborted!
Mysql::Error: #42S02Unknown table ‘photos’: DROP TABLE photos

<!—MIGRATE BACK-UP -->

== CreateSlideshows: migrating ==================
– create_table(“slideshows”)
-> 0.1500s
== CreateSlideshows: migrated (0.1500s) ===========

== CreateSlides: migrating =====================
– create_table(“slides”)
-> 0.1200s
== CreateSlides: migrated (0.1200s) ===============

Thanks for your time Weverton, I appreciate it! To answer your
question, no. This is the output;

±-----------------------------+
| Tables_in_photos_development |
±-----------------------------+
| schema_info |
±-----------------------------+
1 row in set (0.00 sec)

In your database, is there any table after you run rake migrate
VERSION=0??
Ignore schema_info table.

2007/2/25, __ myIP [email protected]:

rake (0.7.1)
Ruby based make-like utility.


Posted via http://www.ruby-forum.com/.


Weverton G. de Morais
Tecnólogo em Redes de Comunicação
Desenvolvedor Delphi

OK,

What’s the value o field version of schema_info table?? What’s the field
value after you run rake migrate??

2007/2/25, __ myIP [email protected]:

1 row in set (0.00 sec)


Posted via http://www.ruby-forum.com/.


Weverton G. de Morais
Tecnólogo em Redes de Comunicação
Desenvolvedor Delphi

Did you try erase this file and run rake migrate again??

2007/2/25, __ myIP [email protected]:

t.column "created_at", :datetime

end

end


Posted via http://www.ruby-forum.com/.


Weverton G. de Morais
Tecnólogo em Redes de Comunicação
Desenvolvedor Delphi

Did you try erase this file and run rake migrate again??

Yes, i just did. It auto-generates the same file, same code.

What’s the value o field version of schema_info table?? What’s the field
value after you run rake migrate??

I am not sure what exactly you are asking. I am not sure what ‘field
version’ means or how to look inside of schema_info.

However the code below is from ‘schema.rb’ file. I noticed when I
migrate to version 0 the ‘Date Modified’ field in Windows doesn’t
change. But when I migrate up to version 3 the ‘Date Modified’ field
does change. However when it migrates up to version 3 it does not
change any data inside of it. It just resaves it, I am assuming. So
the code inside the file never changes between versions.

Does this answer your question? Thanks.

ActiveRecord::Schema.define(:version => 3) do

create_table “slides”, :force => true do |t|
t.column “position”, :integer
t.column “photo_id”, :integer
t.column “slideshow_id”, :integer
end

create_table “slideshows”, :force => true do |t|
t.column “name”, :string
t.column “created_at”, :datetime
end

end

Hmmm…that didn’t work for me, but thanks for the suggestion! I will
keep that in mind next time I run into a rake problem.

What I am trying to do should work, correct? I am not doing anything
out of the norm am I?

I had a similar problem. I did a “rake db:migrate VERSION=0”
and then deleted the schema.rb file. I then did a normal
“rake db:migrate” and everything worked fine.

Jim

I have found that running a development server (./scripts/server)
while doing migrations can help as the SQL statements being generated
and the DB servers responses appear in the logs. This can help track
down errors.

anyone!?

Thanks askegg for the feedback however I was unable to run the
development server. I redid the whole project and it works fine now.

I believe that when I manually deleted the table in mySql it must have
done something that prevented Rails from correctly doing a migrate.

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