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SirBob1701 · May 29th, 2006, 8:34 PM

I'm sorry if this is going to seem like a contrite question but I am new to ruby on rails. I am creating a program for work to keep track of vehicles and their maintence and I am using a mysql relational database. I am having a hard time listing anything that besides the main parent table. That is I can list all the trucks we have that are in the truck table but I cannot list their last oilchanges and such. here are the db diagram and the acutal code (codes a bit messy)

http://sirbob1701.googlepages.com/VehicleLog.bmp
http://sirbob1701.googlepages.com/VehicleLog.zip

Arevos · May 30th, 2006, 3:51 AM

The reason for this is that Ruby on Rails can only find the relationship between two tables automatically if you adhere to certain conventions.

By default, Rails will look for a primary key called "id", and foreign key table connectors called "<tablename>_id". Your database does not adhere to these defaults, therefore Rails cannot automatically find the right connections. Here's some information on these "magic" field names.

To fix your problem, you need to either modify the database to adhere to the defaults, or explicitly tell Rails the names of the key columns (see here). For instance:

truck.rb:

(Toggle Plain Text)

class Truck < ActiveRecord::Base
	set_primary_key 'OilID'
	has_many :oils, :foreign_key => 'vehicleID'
end

oil.rb:

(Toggle Plain Text)

class Oil < ActiveRecord::Base
	set_primary_key 'vehicleID'
	belongs_to :truck, :foreign_key => 'vehicleID'
end

SirBob1701 · May 30th, 2006, 10:32 AM

edit

I figured it out i should be
[code = oil.rb]
class Oil < ActiveRecord::Base
set_primary_key 'OilID'
belongs_to :truck, :foreign_key => 'vehicleID'
end
[/code]

[code = truck.rb]
class Truck < ActiveRecord::Base
set_primary_key 'vehicleID'
has_many :oils
end
[/code]

Arevos · May 30th, 2006, 10:39 AM

Oh, yes, sorry; my mistake. Got the primary keys mixed up

SirBob1701 · May 30th, 2006, 10:43 AM

i'm trying this and it won't work. and i don't know if this is the right way to restrict

(Toggle Plain Text)

compile error
./script/../config/../app/views/oil/time.rhtml:49: parse error, unexpected '>'
./script/../config/../app/views/oil/time.rhtml:50: parse error, unexpected kDO, expecting kEND
	        <% truck.oil.each do |oil| ; _erbout.concat "\n"
	                            ^
./script/../config/../app/views/oil/time.rhtml:63: parse error, unexpected kEND, expecting $

Extracted source (around line #49): 

46: 	<td width="21%"><p align="center"><i><b>Is it Over Due? </b></i></td>
47:  <% @trucks.each do |truck| %>
48:  <tr>
49:    <% unless (truck.oil.vehicleID != truck.vehicleID?) %%>
50: 	        <% truck.oil.each do |oil| %>
51: 	<td><%= truck.vehicle %>
52: 	<td><%= oil.lastMile %></td>

Arevos · May 30th, 2006, 10:46 AM

Do you have an "end" for each "do"? If you start a block with "do", you need an "end" to tell Ruby where the block ends.

SirBob1701 · May 30th, 2006, 10:47 AM

yes i do
here is all the code

(Toggle Plain Text)

 <% @trucks.each do |truck| %>
 <tr>
   <% unless (truck.oil.vehicleID != truck.vehicleID?) %%>
	        <% truck.oil.each do |oil| %>
	<td><%= truck.vehicle %>
	<td><%= oil.lastMile %></td>
	<td><%= oil.lastDate%></td>
	<td><%= oil.over%></td>
</tr>
<% end %>
</table>
<% end %>
</center>

SirBob1701 · May 30th, 2006, 10:55 AM

i probably don't need too loops too. but even when i take the top loop out i still get the error

SirBob1701 · May 30th, 2006, 10:56 AM

I changed it and now i get

(Toggle Plain Text)

compile error
./script/../config/../app/views/oil/time.rhtml:50: parse error, unexpected '>'
./script/../config/../app/views/oil/time.rhtml:52: unterminated string meets end of file

Extracted source (around line #50): 

47:  <% @trucks.each do |truck| %>
48:  <tr>
49:  <% truck.oil.each do |oil| %>
50:    <% unless (truck.oil.vehicleID != truck.vehicleID?) %%>
51: 	       
52: 	<td><%= truck.vehicle %>
53: 	<td><%= oil.lastMile %></td>

May 29th, 2006, 8:34 PM	#1
SirBob1701 Newbie Join Date: May 2006 Posts: 20 Rep Power: 0	My Rails Program With Relational DB I'm sorry if this is going to seem like a contrite question but I am new to ruby on rails. I am creating a program for work to keep track of vehicles and their maintence and I am using a mysql relational database. I am having a hard time listing anything that besides the main parent table. That is I can list all the trucks we have that are in the truck table but I cannot list their last oilchanges and such. here are the db diagram and the acutal code (codes a bit messy) http://sirbob1701.googlepages.com/VehicleLog.bmp http://sirbob1701.googlepages.com/VehicleLog.zip

May 30th, 2006, 3:51 AM	#2
Arevos Programming Guru Join Date: Aug 2005 Location: England Posts: 1,499 Rep Power: 4	The reason for this is that Ruby on Rails can only find the relationship between two tables automatically if you adhere to certain conventions. By default, Rails will look for a primary key called "id", and foreign key table connectors called "<tablename>_id". Your database does not adhere to these defaults, therefore Rails cannot automatically find the right connections. Here's some information on these "magic" field names. To fix your problem, you need to either modify the database to adhere to the defaults, or explicitly tell Rails the names of the key columns (see here). For instance: truck.rb: (Toggle Plain Text) class Truck < ActiveRecord::Base set_primary_key 'OilID' has_many :oils, :foreign_key => 'vehicleID' end class Truck < ActiveRecord::Base set_primary_key 'OilID' has_many :oils, :foreign_key => 'vehicleID' end oil.rb: (Toggle Plain Text) class Oil < ActiveRecord::Base set_primary_key 'vehicleID' belongs_to :truck, :foreign_key => 'vehicleID' end class Oil < ActiveRecord::Base set_primary_key 'vehicleID' belongs_to :truck, :foreign_key => 'vehicleID' end

May 30th, 2006, 10:47 AM	#7
SirBob1701 Newbie Join Date: May 2006 Posts: 20 Rep Power: 0	yes i do here is all the code (Toggle Plain Text) <% @trucks.each do \|truck\| %> <tr> <% unless (truck.oil.vehicleID != truck.vehicleID?) %%> <% truck.oil.each do \|oil\| %> <td><%= truck.vehicle %> <td><%= oil.lastMile %></td> <td><%= oil.lastDate%></td> <td><%= oil.over%></td> </tr> <% end %> </table> <% end %> </center> <% @trucks.each do \|truck\| %> <tr> <% unless (truck.oil.vehicleID != truck.vehicleID?) %%> <% truck.oil.each do \|oil\| %> <td><%= truck.vehicle %> <td><%= oil.lastMile %></td> <td><%= oil.lastDate%></td> <td><%= oil.over%></td> </tr> <% end %> </table> <% end %> </center>

May 30th, 2006, 10:56 AM	#9
SirBob1701 Newbie Join Date: May 2006 Posts: 20 Rep Power: 0	I changed it and now i get (Toggle Plain Text) compile error ./script/../config/../app/views/oil/time.rhtml:50: parse error, unexpected '>' ./script/../config/../app/views/oil/time.rhtml:52: unterminated string meets end of file Extracted source (around line #50): 47: <% @trucks.each do \|truck\| %> 48: <tr> 49: <% truck.oil.each do \|oil\| %> 50: <% unless (truck.oil.vehicleID != truck.vehicleID?) %%> 51: 52: <td><%= truck.vehicle %> 53: <td><%= oil.lastMile %></td> compile error ./script/../config/../app/views/oil/time.rhtml:50: parse error, unexpected '>' ./script/../config/../app/views/oil/time.rhtml:52: unterminated string meets end of file Extracted source (around line #50): 47: <% @trucks.each do \|truck\| %> 48: <tr> 49: <% truck.oil.each do \|oil\| %> 50: <% unless (truck.oil.vehicleID != truck.vehicleID?) %%> 51: 52: <td><%= truck.vehicle %> 53: <td><%= oil.lastMile %></td>

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May 30th, 2006, 10:32 AM	#3
SirBob1701 Newbie Join Date: May 2006 Posts: 20 Rep Power: 0	edit I figured it out i should be [code = oil.rb] class Oil < ActiveRecord::Base set_primary_key 'OilID' belongs_to :truck, :foreign_key => 'vehicleID' end [/code] [code = truck.rb] class Truck < ActiveRecord::Base set_primary_key 'vehicleID' has_many :oils end [/code]

May 30th, 2006, 10:39 AM	#4
Arevos Programming Guru Join Date: Aug 2005 Location: England Posts: 1,499 Rep Power: 4	Oh, yes, sorry; my mistake. Got the primary keys mixed up

May 30th, 2006, 10:43 AM	#5
SirBob1701 Newbie Join Date: May 2006 Posts: 20 Rep Power: 0	i'm trying this and it won't work. and i don't know if this is the right way to restrict (Toggle Plain Text) compile error ./script/../config/../app/views/oil/time.rhtml:49: parse error, unexpected '>' ./script/../config/../app/views/oil/time.rhtml:50: parse error, unexpected kDO, expecting kEND <% truck.oil.each do \|oil\| ; _erbout.concat "\n" ^ ./script/../config/../app/views/oil/time.rhtml:63: parse error, unexpected kEND, expecting $ Extracted source (around line #49): 46: <td width="21%"><p align="center"><i><b>Is it Over Due? </b></i></td> 47: <% @trucks.each do \|truck\| %> 48: <tr> 49: <% unless (truck.oil.vehicleID != truck.vehicleID?) %%> 50: <% truck.oil.each do \|oil\| %> 51: <td><%= truck.vehicle %> 52: <td><%= oil.lastMile %></td> compile error ./script/../config/../app/views/oil/time.rhtml:49: parse error, unexpected '>' ./script/../config/../app/views/oil/time.rhtml:50: parse error, unexpected kDO, expecting kEND <% truck.oil.each do \|oil\| ; _erbout.concat "\n" ^ ./script/../config/../app/views/oil/time.rhtml:63: parse error, unexpected kEND, expecting $ Extracted source (around line #49): 46: <td width="21%"><p align="center"><i><b>Is it Over Due? </b></i></td> 47: <% @trucks.each do \|truck\| %> 48: <tr> 49: <% unless (truck.oil.vehicleID != truck.vehicleID?) %%> 50: <% truck.oil.each do \|oil\| %> 51: <td><%= truck.vehicle %> 52: <td><%= oil.lastMile %></td>

May 30th, 2006, 10:46 AM	#6
Arevos Programming Guru Join Date: Aug 2005 Location: England Posts: 1,499 Rep Power: 4	Do you have an "end" for each "do"? If you start a block with "do", you need an "end" to tell Ruby where the block ends.

May 30th, 2006, 10:55 AM	#8
SirBob1701 Newbie Join Date: May 2006 Posts: 20 Rep Power: 0	i probably don't need too loops too. but even when i take the top loop out i still get the error

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Programming Forums > Script Programming > Ruby

My Rails Program With Relational DB