MySql Errors On .save

Rails
1

Hi All,

I am a real neophyte with Rails and am struggling with something. I hope
you can point me in the right direction.

I have a model of an object that

class Thing< ActiveRecord::Base
attr_accessor :locator_id
has_one :otherthing
has_one :differentthing
end

I can create and delete these things until the cows come home. However,
trying to change the data and save/update I get a rendered SQL error in
the form:

ActionView::TemplateError (Mysql::Error: You have an error in your SQL
syntax; check the manual that corresponds to your MySQL server version
for the right syntax to use near ‘WHERE id = 40’ at line 1: UPDATE
things SET WHERE id = 40)…etc.

So, I reduce this to it’s elements…a find followed immediately
followed by a save and I get this error.

So, it looks to me like a mismatch in the SQL that is generated and the
version of MySql is Server version: 5.0.41 MySQL Community Server (GPL)
and
Rails 1.2.3.

Any help very much appreciated.

Sincerely,

Tim

2

On 1 Nov 2007, at 16:02, Tim W. wrote:

attr_accessor :locator_id
ActionView::TemplateError (Mysql::Error: You have an error in your SQL
syntax; check the manual that corresponds to your MySQL server version
for the right syntax to use near ‘WHERE id = 40’ at line 1: UPDATE
things SET WHERE id = 40)…etc.

So, I reduce this to it’s elements…a find followed immediately
followed by a save and I get this error.

That sql just looks wrong. What columns exist on the table. Are you
passing any extra options into find ?

Fred

3

Frederick C. wrote:

On 1 Nov 2007, at 16:02, Tim W. wrote:

attr_accessor :locator_id
ActionView::TemplateError (Mysql::Error: You have an error in your SQL
syntax; check the manual that corresponds to your MySQL server version
for the right syntax to use near ‘WHERE id = 40’ at line 1: UPDATE
things SET WHERE id = 40)…etc.

So, I reduce this to it’s elements…a find followed immediately
followed by a save and I get this error.

That sql just looks wrong. What columns exist on the table. Are you
passing any extra options into find ?

Fred

Hi Fred,

Thank you for taking a look. I agree the SQL just looks wroung. The SET
in particular is wierd.

Below my sig I have:

  1. Reproducing it with the console
  2. The card object
  3. The cardfront object
  4. The cardback object
  5. The (3) tables involved.

Imagine modeling a playing card. A card “has a” cardfront and a
cardback.

Any help very much appreciated.

Tim

  1. Reproducing it with the console
    Loading development environment.

@card = Card.find(:first, :conditions => 40)
=> #<Card:0x3563904 @attributes={“id”=>“40”}>

@card.save
ActiveRecord::StatementInvalid: Mysql::Error: You have an error in your
SQL syntax; check the manual that corresponds to your MySQL server
version for the right syntax to use near ‘WHERE id = 40’ at line 1:
UPDATE cards SET WHERE id = 40

  1. The card object
    class Card < ActiveRecord::Base
    has_one :cardfront
    has_one :cardback
    end

  2. The cardfront object
    class Cardfront < ActiveRecord::Base
    belongs_to :card
    end

  3. The cardback object
    class Cardback < ActiveRecord::Base
    belongs_to :card
    end

The tables look like:
CREATE TABLE cards (
id int(11) NOT NULL auto_increment,
PRIMARY KEY (id)
)

CREATE TABLE cardfronts (
id int(11) NOT NULL auto_increment,
theme text,
priority int(11) default NULL,
estimate int(11) default NULL,
notes text,
card_id int(11) default NULL,
PRIMARY KEY (id)
)

CREATE TABLE cardbacks (
id int(11) NOT NULL auto_increment,
card_id int(11) default NULL,
PRIMARY KEY (id)
)

4

On 1 Nov 2007, at 17:24, Tim W. wrote:

things SET WHERE id = 40)…etc.

Thank you for taking a look. I agree the SQL just looks wroung. The
SET
in particular is wierd.

I’ve looked at the source and this is just a bug in rails. It’s just
not expecting a table with no attributes other than the primary key.

Fred

5

Frederick C. wrote:

On 1 Nov 2007, at 17:24, Tim W. wrote:

things SET WHERE id = 40)…etc.

Thank you for taking a look. I agree the SQL just looks wroung. The
SET
in particular is wierd.

I’ve looked at the source and this is just a bug in rails. It’s just
not expecting a table with no attributes other than the primary key.

Fred

I am indebted. I was wondering about that, but the add’s and delete’s
worked fine and being new to Rails (and to ORM in general) thought I was
being really stupid. Makes sense now that you’ve sussed it out, the SET
would have a collection of attributes, which just ainna there, I’m
assuming.

Thank you Frederik, hope I can return the favor someday.

Sincerely,

Tim