I just want to make sure I''m doing this properly. I have one table that acts as a primary key: Table : teams team_id name All of my other tables have the following criteria: team_id stats.. more stats.. even more stats.. The foreign key is team_id. So, I''m trying to understand how to associate the other tables through the teams table.. I''ve normalized my tables but I''m just a bit sketchy on how to proceed from here. Should I use simple keys or should I use something like has_many or belongs_to in my associations? When I display a view to another person, I will be displaying the following information: Name stats.. more stats.. even more stats.. stats created by mathematical methods applied to the stats above.. Any tips would be appreciated.. Meanwhile, I will continue reading the rails enterprise book on DB models.. -- Posted via http://www.ruby-forum.com/.
I understand the foreign id has to have the same association id in the naming.. for instance,.. class PassingOffense belongs_to :team end class ScoringOffense belongs_to :team end class Teams has_many :passing_offenses has_many :scoring_offenses end Correct? Or, should I be doing something different here? Keep in mind all tables have team_id but only Teams has the team''s ''name''. -- Posted via http://www.ruby-forum.com/.
On Jun 25, 8:22 pm, "Älphä Blüë" <rails-mailing-l...-ARtvInVfO7m5VldFQK4jKA@public.gmane.orgt> wrote:> I just want to make sure I''m doing this properly. I have one table that > acts as a primary key:No. Tables do not act as primary keys. Fields act as primary keys for tables.> > Table : teams > team_id > nameActiveRecord expects the primary key for the table to be called simply "id", not "whatever_id", although you can override this if you want. In fact, the migrations will automatically create an id field if you don''t specify it.> > All of my other tables have the following criteria: > team_id > stats.. > more stats.. > even more stats.. > > The foreign key is team_id. So, I''m trying to understand how to > associate the other tables through the teams table..Probably through the Team model. You know... @team = Team.find(:some => :conditions) @team.stats @team.more_stats> > I''ve normalized my tables but I''m just a bit sketchy on how to proceed > from here. Should I use simple keys or should I use something like > has_many or belongs_to in my associations?That''s not an "or" question. has_many and belongs_to are the way you tell Rails about your table associations -- it''s not smart enough to infer them from the schema, although I seem to recall the foreign_key_associations plugin can do that. I''ve never used that plugin, though -- I generally would rather specify associations explicitly.> > When I display a view to another person, I will be displaying the > following information: > > Name > stats.. > more stats.. > even more stats.. > stats created by mathematical methods applied to the stats above.. > > Any tips would be appreciated..See above.> > Meanwhile, I will continue reading the rails enterprise book on DB > models..I suspect it may assume a level of SQL and RDBMS knowledge that you probably lack at present... Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org
On Jun 25, 8:48 pm, "Älphä Blüë" <rails-mailing-l...-ARtvInVfO7m5VldFQK4jKA@public.gmane.orgt> wrote:> I understand the foreign id has to have the same association id in the > naming..By default, yes. If the foreign key field has a different name, you can specify that.> for instance,.. > > class PassingOffense > belongs_to :team > end > > class ScoringOffense > belongs_to :team > end > > class Teams > has_many :passing_offenses > has_many :scoring_offenses > end > > Correct?Almost correct -- class Teams should be class Team (remember, model class names are always singular in Rails). This will expect a team_id column in the passing_offenses and scoring_offenses tables, and will create Team#passing_offenses, Team#scoring_offenses, and other methods (see Association docs for the full list).> Or, should I be doing something different here? Keep in mind > all tables have team_id but only Teams has the team''s ''name''.No, other than the pluralization of Teams, this looks pretty good. Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org
Thanks Marnen, So basically: Teams has id name Other tables have team_id stats more_stats still_more_stats .. then the model is singular class Team has_many :passing_offenses has_many :scoring_offenses end and the other tables use team_id as the foreign key association.. class PassingOffense belongs_to :team end class ScoringOffense belongs_to :team end Then I just need to define my queries. I''m better when I see them so I''ll try some of your examples in the console and see how the output works. Thanks mate. -- Posted via http://www.ruby-forum.com/.
2009/6/26 Älphä Blüë <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>:> > ... > Then I just need to define my queries. I''m better when I see them so > I''ll try some of your examples in the console and see how the output > works. >You might well find it worth while looking through some of the guides at guides.rubyonrails.org particularly the one on Active Record Associations. This will provide some very useful tips on how to go about organising and accessing the data. Colin
That was really a great guide. I understand the associations a lot
better now. However, I didn''t see any detailed examples on querying in
the associations guide. Based on what I read and looking over my
database tables, I will definitely be using a belongs_to and has_many
association.
So, for instance..
class Team
has_many :rushing_offenses
end
class RushingOffense
belongs_to :team
end
Table teams:
id
name
Table rushing_offense:
team_id
statone
stattwo
statthree
compiled_on
The name column in teams has to be unique, meaning there will always
only be 120 teams assigned to 120 ids.
So, if I''m creating both a new record in both tables, I''m
using
something similar to this?
@rushing_offense = @team.rushing_offenses.create(:name =>
''Florida'',
:statone => ''143'', :stattwo => ''173'',
:statthree => ''194'',
:compiled_on => Time.now)
The id would automatically be created in the Teams table and because the
foreign key is team_id, that would automatically match when the record
is created? This is the part I''m leery about.
Now the other issue I have is when I do further updating. For instance,
I compiled weekly data. This means that in the rushing_offense table
there will always be 120 records for each week (matching the same number
of teams). I create new records and then view the data based on the
current week, doing something similar by referencing a named_scope:
named_scope :compiled_this_week, lambda { { :conditions =>
[''compiled_on > ? and compiled_on < ?'',
Time.now.beginning_of_week,
Time.now.end_of_week] } }
So, the question is when I go to create the new week''s data,
isn''t an
error going to be thrown in the teams table because it sees that a
unique team is trying to be created? Or, it will it simply not create a
new team/id in the teams table but go ahead and create the data in the
rushing_offense table?
Again, these are specific questions that I have. I need to ensure that
I''m able to create weekly data and find weekly data. In my past model
it was easy because I just had everything duplicated in every table and
queried by a given table. However, it was an incorrect way of doing
things and the tables were not normalized. Now they are.
Please advise...
--
Posted via http://www.ruby-forum.com/.
2009/6/26 Älphä Blüë <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>:> > That was really a great guide. I understand the associations a lot > better now. However, I didn''t see any detailed examples on querying in > the associations guide. Based on what I read and looking over my > database tables, I will definitely be using a belongs_to and has_many > association. >Querying is where the magic of rails comes into play. You can use this_team = Team.find(id) to pick up a particular team or this_team Team.find_by_name( ''some team name''). Then this_team.rushing_offenses will give you an array of all the rushing offenses for this team.> So, for instance.. > > class Team > has_many :rushing_offenses > end > > class RushingOffense > belongs_to :team > end > > Table teams: > id > name > > Table rushing_offense:The table name should be plural - rushing_offenses> team_id > statone > stattwo > statthree > compiled_on > > The name column in teams has to be unique, meaning there will always > only be 120 teams assigned to 120 ids. > > So, if I''m creating both a new record in both tables, I''m using > something similar to this? > > @rushing_offense = @team.rushing_offenses.create(:name => ''Florida'', > :statone => ''143'', :stattwo => ''173'', :statthree => ''194'', > :compiled_on => Time.now) >I have not done it in this way as I have generally created things using the standard methods using form submission. I would suggest you work through some of the other guides also if you haven''t done so already. Then I suggest you play about a bit to see how it all works. When things don''t seem to be doing what you expect the ruby debugger can be very useful (I think there is a guide on using ruby-debug). Also have a look at the guide on testing and start doing tests right from the the beginning. Did you build your models, views etc using the scaffold generator so all the test skeletons have been provided for you? Colin
Hi Colin,
I created rspec_scaffolds with both the teams and rushing_offenses
table. It was pluralized - my apologies. Here''s the schema:
Teams Table:
class CreateTeams < ActiveRecord::Migration
def self.up
create_table :teams do |t|
t.string :name, :unique => true
t.timestamps
end
end
def self.down
drop_table :teams
end
end
Rushing Offenses Table:
class CreateRushingOffenses < ActiveRecord::Migration
def self.up
create_table :rushing_offenses do |t|
t.integer :team_id
t.integer :games
t.integer :carries
t.integer :net
t.integer :tds
t.integer :wins
t.integer :losses
t.integer :ties
t.datetime :compiled_on
t.timestamps
end
end
def self.down
drop_table :rushing_offenses
end
end
The models are:
class Teams < ActiveRecord::Base
has_many :rushing_offenses
end
Didn''t realize that the scaffold would pluralize that - strange.
class RushingOffense < ActiveRecord::Base
belongs_to :team
end
==============================================
Now, I won''t post every bit of code because it would take away from the
topic at hand. But, I use a rake task that is run by cron to call a
scraper.rb file through the rushing_offense model to parse data from
other sites which it then populates my rushing_offense table with.
However, that was before I made changes so it has to be done differently
now.
So, it looks similar to this:
Rake -> update_rushing = RushingOffense.new
--> update_rushing.scrape(arguments)
RushingOffense model houses a scrape method that calls a file called
scraper.rb and parses out the data from the site into an array of
arrays. It then creates the new data, populating the data using
something similar:
RushingOffense.create(:rank => offensive_rushing.rows[i][0],
:name => offensive_rushing.rows[i][1],
:games => offensive_rushing.rows[i][2],
:carries => offensive_rushing.rows[i][3],
:net => offensive_rushing.rows[i][4],
:avg => offensive_rushing.rows[i][5],
:tds => offensive_rushing.rows[i][6],
:ydspg => offensive_rushing.rows[i][7],
:wins => offensive_rushing.rows[i][8],
:losses => offensive_rushing.rows[i][9],
:ties => offensive_rushing.rows[i][10],
:compiled_on => Time.now)
Now, this has all changed because by normalizing my tables, I moved the
name into the Teams table. I also removed rank (because it wasn''t
fully
dependent on the primary key). I also removed avg and ydspg because I
could gain these values by doing calculations later on and so they also
were not dependent on the primary key). So, by normalizing my tables it
has created issues for me in terms of how I scrape and populate the
tables.
I''m just not sure how to tie the two tables in when creating a record.
I will more than likely populate the teams table myself to create the
default 120 teams and their IDs. But, all of my stat tables need to
know that when a record is created, the team_id needs to match the id in
the teams table. Again, I just don''t know how to create this query
based on my examples above.
Keep in mind that the rake task runs weekly so it populates new data
each and every week for each of the stat tables.
In the end, my tables should look like so:
Teams
id = 1
name = Alabama
id = 2
name = Auburn
etc.
up to 120 teams
Rushing_Offenses
team_id = 1
statone = 100
stattwo = 200
statthree = 300
team_id = 2
statone = 100
stattwo = 200
statthree = 300
etc..
up to 120 teams for that week''s rake task
The next week will do the same thing for Rushing Offenses, only the
differing data will be the time it was created/compiled on (which is the
search parameter I use on my views).
So, how do I create one single row of data using the example above if
the Teams table is pre-populated with 120 unique IDs and Teams and the
Rushing Offenses table needs to know which team_id it belongs to?
When parsing the data, all information is stored in the arrays so the
name of the team is shown. I would imagine that the name of the team
would have to be matched to the team name in the teams column and that
the id would then be passed back to the team_id, or I could be
completely mistaken.
As I have a very unique parsing mechanism, and I''ve read a lot of
articles now, some of this just doesn''t make sense to me. A lot of it
has to do with the wordiness of the articles and the way my mind works.
They talk about orders and customers and I have to change the
associations to what I''m working with in order to understand it a lot
of
times.
I''m just better with reading code than I am with anything. If you give
me a paragraph describing how standard deviation works for instance, it
would go over my head. If you write out a standard deviation formula, I
understand it perfectly.
--
Posted via http://www.ruby-forum.com/.
I am afraid I am getting out of my depth with what you are describing below as it is not the sort of application I have experience of. I think you may need help from others. Your Team model class should definitely be singular though. I still think you might be better to work through some of the tutorials working through what one might describe as a typical application in order that you pick up the concepts, then adapt these to your requirements. I suspect you may have a lot of difficulty leaping in at the deep end with a non-conventional application. Colin 2009/6/26 Älphä Blüë <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>:> > Hi Colin, > > I created rspec_scaffolds with both the teams and rushing_offenses > table. It was pluralized - my apologies. Here''s the schema: > > Teams Table: > > class CreateTeams < ActiveRecord::Migration > def self.up > create_table :teams do |t| > t.string :name, :unique => true > > t.timestamps > end > end > > def self.down > drop_table :teams > end > end > > Rushing Offenses Table: > > class CreateRushingOffenses < ActiveRecord::Migration > def self.up > create_table :rushing_offenses do |t| > t.integer :team_id > t.integer :games > t.integer :carries > t.integer :net > t.integer :tds > t.integer :wins > t.integer :losses > t.integer :ties > t.datetime :compiled_on > > t.timestamps > end > end > > def self.down > drop_table :rushing_offenses > end > end > > The models are: > > class Teams < ActiveRecord::Base > has_many :rushing_offenses > end > > Didn''t realize that the scaffold would pluralize that - strange. > > class RushingOffense < ActiveRecord::Base > belongs_to :team > end > > ==============================================> > Now, I won''t post every bit of code because it would take away from the > topic at hand. But, I use a rake task that is run by cron to call a > scraper.rb file through the rushing_offense model to parse data from > other sites which it then populates my rushing_offense table with. > However, that was before I made changes so it has to be done differently > now. > > So, it looks similar to this: > > Rake -> update_rushing = RushingOffense.new > --> update_rushing.scrape(arguments) > > RushingOffense model houses a scrape method that calls a file called > scraper.rb and parses out the data from the site into an array of > arrays. It then creates the new data, populating the data using > something similar: > > RushingOffense.create(:rank => offensive_rushing.rows[i][0], > :name => offensive_rushing.rows[i][1], > :games => offensive_rushing.rows[i][2], > :carries => offensive_rushing.rows[i][3], > :net => offensive_rushing.rows[i][4], > :avg => offensive_rushing.rows[i][5], > :tds => offensive_rushing.rows[i][6], > :ydspg => offensive_rushing.rows[i][7], > :wins => offensive_rushing.rows[i][8], > :losses => offensive_rushing.rows[i][9], > :ties => offensive_rushing.rows[i][10], > :compiled_on => Time.now) > > Now, this has all changed because by normalizing my tables, I moved the > name into the Teams table. I also removed rank (because it wasn''t fully > dependent on the primary key). I also removed avg and ydspg because I > could gain these values by doing calculations later on and so they also > were not dependent on the primary key). So, by normalizing my tables it > has created issues for me in terms of how I scrape and populate the > tables. > > I''m just not sure how to tie the two tables in when creating a record. > > I will more than likely populate the teams table myself to create the > default 120 teams and their IDs. But, all of my stat tables need to > know that when a record is created, the team_id needs to match the id in > the teams table. Again, I just don''t know how to create this query > based on my examples above. > > Keep in mind that the rake task runs weekly so it populates new data > each and every week for each of the stat tables. > > In the end, my tables should look like so: > > Teams > id = 1 > name = Alabama > id = 2 > name = Auburn > etc. > up to 120 teams > > Rushing_Offenses > team_id = 1 > statone = 100 > stattwo = 200 > statthree = 300 > team_id = 2 > statone = 100 > stattwo = 200 > statthree = 300 > etc.. > up to 120 teams for that week''s rake task > > The next week will do the same thing for Rushing Offenses, only the > differing data will be the time it was created/compiled on (which is the > search parameter I use on my views). > > So, how do I create one single row of data using the example above if > the Teams table is pre-populated with 120 unique IDs and Teams and the > Rushing Offenses table needs to know which team_id it belongs to? > > When parsing the data, all information is stored in the arrays so the > name of the team is shown. I would imagine that the name of the team > would have to be matched to the team name in the teams column and that > the id would then be passed back to the team_id, or I could be > completely mistaken. > > As I have a very unique parsing mechanism, and I''ve read a lot of > articles now, some of this just doesn''t make sense to me. A lot of it > has to do with the wordiness of the articles and the way my mind works. > They talk about orders and customers and I have to change the > associations to what I''m working with in order to understand it a lot of > times. > > I''m just better with reading code than I am with anything. If you give > me a paragraph describing how standard deviation works for instance, it > would go over my head. If you write out a standard deviation formula, I > understand it perfectly. > > -- > Posted via http://www.ruby-forum.com/. > > > >
Well I hate to say I took the easier way but with this scenario I did. I went back to the older way of doing things with regards to only the statistics tables. The way I see it is they are being parsed from another table and so therefore, they are just table lists for the most part. They are individual from one another and supply distinct views of a particular category. Therefore, there really is no association with them other than them just being viewed as is... The only table I will be using to work with them is my ratings table and for that I''m using calculations only. So, I can pull the particular piece of information I need from each of the tables I have currently and create calculations which are then built into the ratings view. For other parts of my site, I will be using normalization and working on understanding these associations better. Again, like you said... I was trying to do too much. I can''t hurt any of my views doing it the way I am currently. If I were populating the data inwardly and not relying on an external source/parser - maybe then I would have to normalize and change things. Thanks for all your help though. I did create a viewer/category/links association using a tutorial I found online that allowed me to create a resources links table. It did help me understand association better. -- Posted via http://www.ruby-forum.com/.
On Jun 26, 11:55 am, "Älphä Blüë" <rails-mailing-l...@andreas-s.net> wrote: [...] RushingOffense model houses a scrape method that calls a file called> scraper.rb and parses out the data from the site into an array of > arrays. It then creates the new data, populating the data using > something similar: > > RushingOffense.create(:rank => offensive_rushing.rows[i][0], > :name => offensive_rushing.rows[i][1], > :games => offensive_rushing.rows[i][2], > :carries => offensive_rushing.rows[i][3], > :net => offensive_rushing.rows[i][4], > :avg => offensive_rushing.rows[i][5], > :tds => offensive_rushing.rows[i][6], > :ydspg => offensive_rushing.rows[i][7], > :wins => offensive_rushing.rows[i][8], > :losses => offensive_rushing.rows[i][9], > :ties => offensive_rushing.rows[i][10], > :compiled_on => Time.now)---begin style-Nazi digression--- Just as an aside: this is rather unidiomatic Ruby. Why didn''t you assign offensive_rushing.rows[i] to a local variable and save some typing (and possibly some calculation time)? Worse, the [i] makes me think that you''re using a for loop of some sort. Remember, Ruby is not PHP, and it has different looping constructs. You want rows.each. Or you could do something like this: FIELDS = [:rank, :name, :games, ...] offensive_rushing.rows.each do |row| values = {:compiled_on => Time.now} FIELDS.each_with_index do |field, i| values[field] = row[i] end RushingOffense.create values end ...which is shorter and arguably easier to read. -----end style-Nazi digression----- Also note that you''re doing a separate DB query for each record created, which is a terrible idea (queries don''t belong inside loops). Investigate ar-extensions or some other bulk insertion plugin, or if all else fails, generate a bulk insert statement directly in SQL.> > Now, this has all changed because by normalizing my tables, I moved the > name into the Teams table. I also removed rank (because it wasn''t fully > dependent on the primary key). I also removed avg and ydspg because I > could gain these values by doing calculations later on and so they also > were not dependent on the primary key). So, by normalizing my tables it > has created issues for me in terms of how I scrape and populate the > tables. > > I''m just not sure how to tie the two tables in when creating a record.Simple: team_name = offensive_rushing.rows[i][1] # (or whatever the proper array subscript is) team = Team.find_by_name(team_name) # and then either: team.rushing_offenses << RushingOffense.create(:whatever => ''data'', :you => ''want'') # or: RushingOffense.create(:team => team, :other => ''data'') Rails does most of the work for you. [...]> So, how do I create one single row of data using the example above if > the Teams table is pre-populated with 120 unique IDs and Teams and the > Rushing Offenses table needs to know which team_id it belongs to?That''s how.> > When parsing the data, all information is stored in the arrays so the > name of the team is shown. I would imagine that the name of the team > would have to be matched to the team name in the teams column and that > the id would then be passed back to the team_id, or I could be > completely mistaken.You are completely correct. That''s what the Team.find_by_name line above does.> > As I have a very unique parsing mechanism, and I''ve read a lot of > articles now, some of this just doesn''t make sense to me.Your parsing mechanism is irrelevant. You just need to know what to do with the data once parsed. Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org
On Jun 26, 3:13 pm, "Älphä Blüë" <rails-mailing-l...-ARtvInVfO7m5VldFQK4jKA@public.gmane.orgt> wrote:> Well I hate to say I took the easier way but with this scenario I did. > I went back to the older way of doing things with regards to only the > statistics tables.Bad idea. Proper use of associated tables is so fundamental to efficient application design -- and so well supported in Rails -- that it is worth holding up further development until you understand it. I try not to be dogmatic about many things, but this is one of them. See my other recent post in this thread for sample ideas. Really, *learn to use the framework and the database*, don''t just kludge your way around them. Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org
Hi Marnen,
Well I have multiple copies of my project (one on 1.9.1 with mysql,
another on 1.8.6 with postgres, and another on 1.8.6 with mysql). I
also keep a full backup of each with subversion and hard-copied.
So, I played around with the parser object first, using your
suggestions. I came up with:
FIELDS = [:rank, :name, :games, :carries, :net, :avg, :tds, :ydspg,
:wins, :losses, :ties]
def scrape(url,type,name,deep)
# scraping/parsing our data
offensive_rushing = Scraper.new(url,type,name,deep)
offensive_rushing.scrape_data
offensive_rushing.clean_celldata
# checking to see if the data exists in our table for the current
week
@rushing_offenses = RushingOffense.compiled_this_week.find(:all)
if @rushing_offenses == [] # means we have an empty array so no data
exists
puts "Updating Offensive Rushing Statistics for the following
teams:"
offensive_rushing.rows.each do |row|
values = {:compiled_on => Time.now}
FIELDS.each_with_index do |field, i|
values[field] = row[i]
end
# List our teams
puts row[1]
RushingOffense.create values
end
end
if @rushing_offenses != [] # means the current week''s data is not
empty so don''t update data
puts "Current Week''s Data Is Already Populated!"
end
end
And the parser object works fine with your suggestions. Yes, you were
correct about the for loop. This bit of code you provided helped me
understand how arrays work in a much deeper detail. I''ve been using
ruby''s .each with normal arrays but was having difficulty with array of
arrays. Thanks for shedding the light.
I''ll try your suggestions with my backed up project and mull over
things
a bit. It is very difficult for me to slow down though mate. I''m
patient but that''s not necessarily the same thing. I have a lot of
ideas and I like to play with those ideas. Rails to me is like a giant
candy store and I''m starving and got locked inside.
--
Posted via http://www.ruby-forum.com/.
Älphä Blüë wrote: [...]> And the parser object works fine with your suggestions.Glad to hear it!> Yes, you were > correct about the for loop. This bit of code you provided helped me > understand how arrays work in a much deeper detail. I''ve been using > ruby''s .each with normal arrays but was having difficulty with array of > arrays. Thanks for shedding the light.You''re welcome. The shift from loop indices to iterators can be a little difficult, but it''s worth it.> > I''ll try your suggestions with my backed up projectRemember: version control means never having to say you''re sorry. (Or rather, it makes it easier to say you''re sorry...)> and mull over things > a bit. It is very difficult for me to slow down though mate. I''m > patient but that''s not necessarily the same thing.I understand. The first time I used an app framework, version control, test-first development...the first time I used each of these, it felt like another piece to get in the way. But in each case, it turned out to pave the way for quicker development and better code.> I have a lot of > ideas and I like to play with those ideas.Me too.> Rails to me is like a giant > candy store and I''m starving and got locked inside.Then please, take the time to locate the healthier snacks, or you''ll gorge yourself on sugar and get a horrible stomachache! Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
Marnen,
I managed to get my scraper/parser working as intended with utilizing
both the teams table and the stats table it is updating. I did the
following:
FIELDS = [:rank, :team_id, :games, :carries, :net, :avg, :tds, :ydspg,
:wins, :losses, :ties]
def scrape(url,type,name,deep)
offensive_rushing = Scraper.new(url,type,name,deep)
offensive_rushing.scrape_data
offensive_rushing.clean_celldata
@rushing_offenses = RushingOffense.compiled_this_week.find(:all)
if @rushing_offenses == [] # means we have an empty array so no data
exists
puts "Updating Offensive Rushing Statistics for the following
teams:"
offensive_rushing.rows.each do |row|
team = Team.find_by_name(row[1])
values = {:compiled_on => Time.now}
FIELDS.each_with_index do |field, i|
if row[i] == row[1]
values[field] = team.id
else
values[field] = row[i]
end
end
# List each team we update
puts team.name + " ID = " + team.id.to_s
RushingOffense.create values
end
else
# data is already populated for the week so don''t update
puts "Current Week''s Data Is Already Populated!"
end
end
Basically, since the parser houses the name of the team in row[1] I
simply substituted :name for :team_id in my constant. I then supplied
the team variable per your helpful tidbits and then checked in the each
method to see if row[i] was the same as row[1] and if so to substitute
the values for team.id.
It lines up correctly and appears to function fine. Do you see any
possible errors with my syntax? I just want to make sure I''ve done
this
part right.
So far my teams table is populated with the correct teams and
rushing_offense is populated correctly as well. I''m going to work on
the find..
I also have a question on Constants. In this case, it appears the
FIELDS constant should probably be named to something associated with
the rushing_offense model as it is just going to be used by this model.
But, if I had a constant that needed to be usable by all models would I
put that in environment.rb?
Thanks again mate. Wish me luck on the find queries.
--
Posted via http://www.ruby-forum.com/.
Hrm, okay my tables are setup correctly now and populated so I''m trying to do a find, but I must be doing it wrong.. class Team < ActiveRecord::Base has_many :rushing_offenses end class RushingOffense < ActiveRecord::Base belongs_to :team end I''ve tried the following in the rails console: @team = Team.find(:all) @rushing_offenses = @team.rushing_offenses.find(:all) and get an undefined method rushing_offenses error Again, I''m probably doing this wrong. Let me break it apart the way I believe it''s reading from a code standpoint: @team = Team.find(:all) --> Is finding all the data in the teams table @rushing_offenses = @team.rushing_offenses.find(:all) --> assign an instance variable @rushing_offenses --> utilize the associations with: @team found all data in teams --> utilize the associations with: rushing_offenses (because it belongs to team) --> rushing_offenses.find(:all) would find all data in the rushing_offenses table Yes?.. No?.. I read up on the associations and understand the association thinking and when to use associations. I just don''t understand the code syntax between them and how to use the code syntax for normal querying... -- Posted via http://www.ruby-forum.com/.
I decided to test whether or not I was getting new methods through belongs_to and I''m not. I did: Commented the belongs_to :team and saved the RushingOffense model f = RushingOffense.find :all --> Found all my records original_methods = f.methods --> Listed all of the current methods Uncommented the belongs_to :team and saved the RushingOffense model reload! --> Reloaded the model f = RushingOffense.find :all --> Found all my records new_methods = f.methods --> Listed all of the current methods added_methods = new_methods - original_methods ==> [] (empty) I thought by adding belongs_to I would receive new methods due to the association? Am I mistaken..? -- Posted via http://www.ruby-forum.com/.
Älphä Blüë wrote:> Hrm, okay my tables are setup correctly now and populated so I''m trying > to do a find, but I must be doing it wrong..I think you are.> > class Team < ActiveRecord::Base > has_many :rushing_offenses > end > > class RushingOffense < ActiveRecord::Base > belongs_to :team > end >This is fine.> I''ve tried the following in the rails console: > > @team = Team.find(:all) > @rushing_offenses = @team.rushing_offenses.find(:all) > > and get an undefined method rushing_offenses error >Of course you do. ActiveRecord::Base.find(:all) returns an array of model objects, whereas methods like rushing_offenses are defined on *each* model instance, not on the array as a whole. You need to call rushing_offenses on the particular Team instance that you''re interested in. (And you don''t need the .find(:all) on rushing_offenses.) [...]> > I read up on the associations and understand the association thinking > and when to use associations. I just don''t understand the code syntax > between them and how to use the code syntax for normal querying...I think you understand the syntax. You just seem to be uncertain on what methods are defined on the individual models and what''s defined on the array as a whole. Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
Marnen Laibow-Koser wrote:> I think you understand the syntax. You just seem to be uncertain on > what methods are defined on the individual models and what''s defined on > the array as a whole. >That''s why I figured I would just see which methods were new since I kept getting an undefined method error but as per my example above, the array came up empty. So, according to that bit of code, my associations are not giving me any new methods with which to work with. Again, maybe I''m mistaken here. What would the simplest check be to determine whether or not both models are associated with one another? -- Posted via http://www.ruby-forum.com/.
Älphä Blüë wrote:> I decided to test whether or not I was getting new methods through > belongs_to and I''m not. I did: > > Commented the belongs_to :team and saved the RushingOffense model > > f = RushingOffense.find :all > --> Found all my records > original_methods = f.methods > --> Listed all of the current methods > > Uncommented the belongs_to :team and saved the RushingOffense model > reload! > --> Reloaded the model > f = RushingOffense.find :all > --> Found all my records > new_methods = f.methods > --> Listed all of the current methods > > added_methods = new_methods - original_methods > > ==> [] (empty) > > I thought by adding belongs_to I would receive new methods due to the > association? Am I mistaken..?Well, as I explained in another post, the methods you''ll get are defined on the individual Team objects, not the array. But your methodology here is problematic anyway: all you''re doing is checking the contents of the array returned by Object#methods. Since methods can be created dynamically or faked with method_missing trickery (which AR uses quite often), there may be valid calls that do not appear in the methods array. Therefore, it''s safer to use Object#respond_to? to check this sort of thing. Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
Älphä Blüë wrote: [...]> > What would the simplest check be to determine whether or not both models > are associated with one another?Use reflect_on_association (no, I won''t describe it here -- read the docs). That''s how I usually do it in my RSpec files If you''re using Shoulda, I believe it has ready-made .should_belong_to assertions. Best, -- Marnen Laibow-Koser http://www.marnen.org marnen-sbuyVjPbboAdnm+yROfE0A@public.gmane.org -- Posted via http://www.ruby-forum.com/.
remove the .find(:all), you''ve already found @team so @team.rushing_offenses is all you need. -eric On Jun 27, 8:24 am, "Älphä Blüë" <rails-mailing-l...-ARtvInVfO7m5VldFQK4jKA@public.gmane.orgt> wrote:> Hrm, okay my tables are setup correctly now and populated so I''m trying > to do a find, but I must be doing it wrong.. > > class Team < ActiveRecord::Base > has_many :rushing_offenses > end > > class RushingOffense < ActiveRecord::Base > belongs_to :team > end > > I''ve tried the following in the rails console: > > @team = Team.find(:all) > @rushing_offenses = @team.rushing_offenses.find(:all) > > and get an undefined method rushing_offenses error > > Again, I''m probably doing this wrong. Let me break it apart the way I > believe it''s reading from a code standpoint: > > @team = Team.find(:all) > --> Is finding all the data in the teams table > > @rushing_offenses = @team.rushing_offenses.find(:all) > --> assign an instance variable @rushing_offenses > --> utilize the associations with: @team found all data in teams > --> utilize the associations with: rushing_offenses (because it belongs > to team) > --> rushing_offenses.find(:all) would find all data in the > rushing_offenses table > > Yes?.. No?.. > > I read up on the associations and understand the association thinking > and when to use associations. I just don''t understand the code syntax > between them and how to use the code syntax for normal querying... > > -- > Posted viahttp://www.ruby-forum.com/.
Eric wrote:> remove the .find(:all), you''ve already found @team so > @team.rushing_offenses is all you need. > > -eric > > On Jun 27, 8:24�am, "�lph� Bl��" <rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>Thanks Eric, that''s what I had thought when I read everything Marnen posted afterwards, which is why I tried to find out if maybe I was using the wrong method. But, for instance: @team = Team.find :all @team.rushing_offenses>> @team.rushing_offensesNoMethodError: undefined method ''rushing_offenses'' for #<Array:0x5ae469c> -- Posted via http://www.ruby-forum.com/.
On Jun 27, 3:13 pm, "Älphä Blüë" <rails-mailing-l...-ARtvInVfO7m5VldFQK4jKA@public.gmane.orgt> wrote:> Eric wrote: > > > On Jun 27, 8:24 am, " lph Bl " <rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> > > Thanks Eric, that''s what I had thought when I read everything Marnen > posted afterwards, which is why I tried to find out if maybe I was using > the wrong method. > > But, for instance: > > @team = Team.find :all > @team.rushing_offenses > > >> @team.rushing_offenses > > NoMethodError: undefined method ''rushing_offenses'' for > #<Array:0x5ae469c>Here @team isn''t a team. It''s an array containing all of your teams so you can''t call rushing_offenses (which is an instance method of Team) on it - you''ve got to pull out one particular team and call it on that. Fred> -- > Posted viahttp://www.ruby-forum.com/.
2009/6/27 Älphä Blüë <rails-mailing-list-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>:> > Eric wrote: >> remove the .find(:all), you''ve already found @team so >> @team.rushing_offenses is all you need. >> >> -eric >> >> On Jun 27, 8:24�am, "�lph� Bl��" <rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org> > > Thanks Eric, that''s what I had thought when I read everything Marnen > posted afterwards, which is why I tried to find out if maybe I was using > the wrong method. > > But, for instance: > > @team = Team.find :all > @team.rushing_offenses@team is (effectively) an array of Teams. It must be if you think about it as you you have asked to find all the teams. You might be better to call it @teams Then you can do things like @teams.each do |team| # some code using team.rushing_offenses end Again team.rushing_offenses is an array Colin
Thanks guys,
So after a 36 hours the lightbulb finally clicked in. I think the
greatest issue I found throughout this particular issue wasn''t that I
didn''t hear what some of you were saying to me, it''s that I
couldn''t see
what you were saying to me.
The end result code for finding everything from both associated tables
was:
@rushing_offenses.each do |r|
r.rank
r.team.name # this is the piece I did not understand how to code
r.games
r.etc....
r.etc....
end
I didn''t know how to tie in the two tables code wise when iterating
through each row. A lot of what I read concentrated more on talking
about how associations work but less on how to code a simple select all
rows statement. As I said beforehand, I work better when I see code. I
just happened to stumble upon this while doing my own tests.. and then I
understood a bit more..
But, I still have an issue with my list method and using code between
two tables..
For instance,
I have a named_scope for the date between compiles:
named_scope :compiled_this_week, lambda { { :conditions =>
[''compiled_on > ? and compiled_on < ?'', Time.now.beginning_of_week,
Time.now.end_of_week] } }
.. and a list function to paginate my code:
def self.list(search, page, orderby, sortby, numteams)
orderby = "rank" if orderby == nil
orderall = (sortby != ''asc'' && sortby != nil) ?
"DESC" : "ASC"
compiled_this_week.paginate :conditions => [''name like
?'',
"%#{search}%"], :order => orderby + " #{orderall}",
:per_page =>
numteams, :page => page
end
In my index view I''m making a search call to :name,
<% form_tag rushing_offenses_path, :method =>
''get'' do %>
<p>
<%= hinted_text_field_tag :search, params[:search], "Enter
Team" %>
<%= submit_tag "Team Search", :name => nil %>
</p>
<% end %>
But of course the :name is not going to work now. I still do not know
how to change the pagination to work between two tables.
If I find this answer, my brain will not explode but I''ll finally be
able to take a shower and my fiance won''t make me sleep on the couch
tonight.. :)
By the way, Marnen - loved your site and the fact that you are into
SCA..
Colin, Fred, and Eric - all four of you have helped me through a bunch
of things so far. I only hope that one day I''ll be knowledable enough
that I can start answering other peoples'' questions..
--
Posted via http://www.ruby-forum.com/.
Yay - I figured the paginate issue out on my own..
compiled_this_week.paginate :joins => :team, :conditions =>
[''name like
?'', "%#{search}%"], :order => orderby + "
#{orderall}", :per_page =>
numteams, :page => page
just had to add :joins
Very nifty now that I''m seeing how they tie in together. More
lightbulbs coming on..
--
Posted via http://www.ruby-forum.com/.