Rails data modelling with has_many through
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Pradeep Achuthan
Aug 19, 2015, 1:06:46 AM8/19/15
to Ruby on Rails: Talk
I am building an expense tracker application and I am in middle of data modelling. I have a Users table. Each user will log his expenses with expense type and income with income type. So I need to know how can we set up associations for it.
As per my understanding I have set it up as follows
User has_many :expenses, through: :transactions
User has_many :incomes, through: :transactions
Expense belongs_to :user
Income belongs_to :user
Here I am not sure what the transaction would associate and also expene/income type.
Any suggestions/insights would be great.
As per my understanding I have set it up as follows
User has_many :expenses, through: :transactions
User has_many :incomes, through: :transactions
Expense belongs_to :user
Income belongs_to :user
Here I am not sure what the transaction would associate and also expene/income type.
Any suggestions/insights would be great.
Colin Law
Aug 19, 2015, 6:03:20 AM8/19/15
to Ruby on Rails: Talk
determines whether you need a transactions table and what should be in
it.
Colin
Elizabeth McGurty
Aug 19, 2015, 11:28:38 AM8/19/15
to Ruby on Rails: Talk
Pradeep, following pertains to more advanced folks here. I thought that demonstrating a good solution would be easy, but I am encountering LocalJumpError: no block given (yield) on transaction_id... I created a transaction table, and referenced it from User has_many. Folks, what the problem there?
Liz
Liz
Colin Law
Aug 19, 2015, 2:31:19 PM8/19/15
to Ruby on Rails: Talk
On 19 August 2015 at 16:28, Elizabeth McGurty <emcg...@gmail.com> wrote:
> Pradeep, following pertains to more advanced folks here. I thought that
> demonstrating a good solution would be easy, but I am encountering
> LocalJumpError: no block given (yield) on transaction_id... I created a
> transaction table, and referenced it from User has_many. Folks, what the
> problem there?
Transaction is a reserved word (for database transactions oddly
> Pradeep, following pertains to more advanced folks here. I thought that
> demonstrating a good solution would be easy, but I am encountering
> LocalJumpError: no block given (yield) on transaction_id... I created a
> transaction table, and referenced it from User has_many. Folks, what the
> problem there?
enough). Change the model name.
Colin
t 19, 2015 at 1:06:46 AM UTC-4, Pradeep Achuthan wrote:
>>
>> I am building an expense tracker application and I am in middle of data
>> modelling. I have a Users table. Each user will log his expenses with
>> expense type and income with income type. So I need to know how can we set
>> up associations for it.
>> As per my understanding I have set it up as follows
>>
>> User has_many :expenses, through: :transactions
>> User has_many :incomes, through: :transactions
>>
>> Expense belongs_to :user
>>
>> Income belongs_to :user
>>
>> Here I am not sure what the transaction would associate and also
>> expene/income type.
>>
>> Any suggestions/insights would be great.
>
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Walter Lee Davis
Aug 19, 2015, 8:07:10 PM8/19/15
to rubyonra...@googlegroups.com
On Aug 19, 2015, at 2:30 PM, Colin Law <cla...@gmail.com> wrote:
> On 19 August 2015 at 16:28, Elizabeth McGurty <emcg...@gmail.com> wrote:
>> Pradeep, following pertains to more advanced folks here. I thought that
>> demonstrating a good solution would be easy, but I am encountering
>> LocalJumpError: no block given (yield) on transaction_id... I created a
>> transaction table, and referenced it from User has_many. Folks, what the
>> problem there?
>
> Transaction is a reserved word (for database transactions oddly
> enough). Change the model name.
I am sure it could use some updating, but it is mostly accurate...
Walter
Elizabeth McGurty
Aug 20, 2015, 11:00:21 AM8/20/15
to Ruby on Rails: Talk
Okay.... I have prepared the following...
First thing is that you need to know a bit about accounting. Accounting involves a (debit/credit) ledger that delineates all business aspects of income, expenses, ....
So to build a web site with tables based on each of these is not, in my opinion, a good idea.
So I offer the following:
Build the tables:
mysql> describe ledgers;
+-------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| ledger_item | varchar(255) | YES | | NULL | |
| created_at | datetime | NO | | NULL | |
| updated_at | datetime | NO | | NULL | |
+-------------+--------------+------+-----+---------+----------------+
4 rows in set (0.01 sec)
migration:
rails generate model ledger ledger_item:string
mysql> describe ledger_lines;
+------------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| ledger_id | int(11) | YES | | NULL | |
| ledger_line_item | varchar(255) | YES | | NULL | |
| created_at | datetime | NO | | NULL | |
| updated_at | datetime | NO | | NULL | |
+------------------+--------------+------+-----+---------+----------------+
5 rows in set (0.01 sec)
migration:
rails generate model ledger_line ledger_id:integer ledger_line_item:string
mysql> describe user_transactions;
+------------------+---------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------------+---------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| user_id | int(11) | YES | | NULL | |
| ledger_id | int(11) | YES | | NULL | |
| ledger_line_id | int(11) | YES | | NULL | |
| line_item_amount | decimal(10,0) | YES | | NULL | |
| created_at | datetime | NO | | NULL | |
| updated_at | datetime | NO | | NULL | |
+------------------+---------------+------+-----+---------+----------------+
7 rows in set (0.01 sec)
migration:
You try to do yourself, based on examples above
You can do your own int size, with or with date fields...
Starting anew...
MODELS:
Assuming you already have a User model/table. For the demonstration your User model should have id: id, and username
class Ledger < ActiveRecord::Base
has_many :ledger_line
has_many :user_transaction
end
class LedgerLine < ActiveRecord::Base
belongs_to :ledger
has_many :user_transaction
end
class UserTransaction < ActiveRecord::Base
belongs_to :user
belongs_to :ledger ## So you can retreive at ledger level
belongs_to :ledger_line ## So you can retrieve at line item level
end
seeds.rb >>> run rake db:seed, after you have created tables via rake db:migrate
# This file should contain all the record creation needed to seed the database with its default values.
# The data can then be loaded with the rake db:seed (or created alongside the db with db:setup).
unless Ledger.count > 0
Ledger.create!(ledger_item: 'expense' ) ## id: 1
Ledger.create!(ledger_item: 'income' ) ## id: 2
end
unless LedgerLine.count > 0
LedgerLine.create!(ledger_id: 1, ledger_line_item: 'travel') ## ledge type expense..
LedgerLine.create!(ledger_id: 1, ledger_line_item: 'office_supplies')
LedgerLine.create!(ledger_id: 1, ledger_line_item: 'meals')
LedgerLine.create!(ledger_id: 2, ledger_line_item: 'commission') ## ledge type income..
LedgerLine.create!(ledger_id: 2, ledger_line_item: 'sales')
LedgerLine.create!(ledger_id: 2, ledger_line_item: 'salary')
end
## I am reusing an existing user table, please disregard email, user_alias, user_type, and is_rapid
unless User.count > 0
User.create!(id: 1, username: 'Pradeep', email: 'f...@foo.foo', user_alias: 'foo', is_rapid: 1, user_type: 1 ) ## id: 1
end
UserTransaction.delete_all
UserTransaction.create!(user_id: 1, ledger_id: 1, ledger_line_id: 1, line_item_amount: 12.50)
UserTransaction.create!(user_id: 1, ledger_id: 1,ledger_line_id: 2, line_item_amount: 102.50)
UserTransaction.create!(user_id: 1, ledger_id: 1,ledger_line_id: 3, line_item_amount: 56.15)
UserTransaction.create!(user_id: 1, ledger_id: 2,ledger_line_id: 4, line_item_amount: 123.56)
UserTransaction.create!(user_id: 1, ledger_id: 2,ledger_line_id: 5, line_item_amount: 45.68)
UserTransaction.create!(user_id: 1, ledger_id: 2,ledger_line_id: 6, line_item_amount: 32.16)
## End of seeds.rb file
#From this you should be able to build associations to retrieve by user, by ledger item, ledge line item
First thing is that you need to know a bit about accounting. Accounting involves a (debit/credit) ledger that delineates all business aspects of income, expenses, ....
So to build a web site with tables based on each of these is not, in my opinion, a good idea.
So I offer the following:
Build the tables:
mysql> describe ledgers;
+-------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| ledger_item | varchar(255) | YES | | NULL | |
| created_at | datetime | NO | | NULL | |
| updated_at | datetime | NO | | NULL | |
+-------------+--------------+------+-----+---------+----------------+
4 rows in set (0.01 sec)
migration:
rails generate model ledger ledger_item:string
mysql> describe ledger_lines;
+------------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| ledger_id | int(11) | YES | | NULL | |
| ledger_line_item | varchar(255) | YES | | NULL | |
| created_at | datetime | NO | | NULL | |
| updated_at | datetime | NO | | NULL | |
+------------------+--------------+------+-----+---------+----------------+
5 rows in set (0.01 sec)
migration:
rails generate model ledger_line ledger_id:integer ledger_line_item:string
mysql> describe user_transactions;
+------------------+---------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------------+---------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| user_id | int(11) | YES | | NULL | |
| ledger_id | int(11) | YES | | NULL | |
| ledger_line_id | int(11) | YES | | NULL | |
| line_item_amount | decimal(10,0) | YES | | NULL | |
| created_at | datetime | NO | | NULL | |
| updated_at | datetime | NO | | NULL | |
+------------------+---------------+------+-----+---------+----------------+
7 rows in set (0.01 sec)
migration:
You try to do yourself, based on examples above
You can do your own int size, with or with date fields...
Starting anew...
MODELS:
Assuming you already have a User model/table. For the demonstration your User model should have id: id, and username
class Ledger < ActiveRecord::Base
has_many :ledger_line
has_many :user_transaction
end
class LedgerLine < ActiveRecord::Base
belongs_to :ledger
has_many :user_transaction
end
class UserTransaction < ActiveRecord::Base
belongs_to :user
belongs_to :ledger ## So you can retreive at ledger level
belongs_to :ledger_line ## So you can retrieve at line item level
end
seeds.rb >>> run rake db:seed, after you have created tables via rake db:migrate
# This file should contain all the record creation needed to seed the database with its default values.
# The data can then be loaded with the rake db:seed (or created alongside the db with db:setup).
unless Ledger.count > 0
Ledger.create!(ledger_item: 'expense' ) ## id: 1
Ledger.create!(ledger_item: 'income' ) ## id: 2
end
unless LedgerLine.count > 0
LedgerLine.create!(ledger_id: 1, ledger_line_item: 'travel') ## ledge type expense..
LedgerLine.create!(ledger_id: 1, ledger_line_item: 'office_supplies')
LedgerLine.create!(ledger_id: 1, ledger_line_item: 'meals')
LedgerLine.create!(ledger_id: 2, ledger_line_item: 'commission') ## ledge type income..
LedgerLine.create!(ledger_id: 2, ledger_line_item: 'sales')
LedgerLine.create!(ledger_id: 2, ledger_line_item: 'salary')
end
## I am reusing an existing user table, please disregard email, user_alias, user_type, and is_rapid
unless User.count > 0
User.create!(id: 1, username: 'Pradeep', email: 'f...@foo.foo', user_alias: 'foo', is_rapid: 1, user_type: 1 ) ## id: 1
end
UserTransaction.delete_all
UserTransaction.create!(user_id: 1, ledger_id: 1, ledger_line_id: 1, line_item_amount: 12.50)
UserTransaction.create!(user_id: 1, ledger_id: 1,ledger_line_id: 2, line_item_amount: 102.50)
UserTransaction.create!(user_id: 1, ledger_id: 1,ledger_line_id: 3, line_item_amount: 56.15)
UserTransaction.create!(user_id: 1, ledger_id: 2,ledger_line_id: 4, line_item_amount: 123.56)
UserTransaction.create!(user_id: 1, ledger_id: 2,ledger_line_id: 5, line_item_amount: 45.68)
UserTransaction.create!(user_id: 1, ledger_id: 2,ledger_line_id: 6, line_item_amount: 32.16)
## End of seeds.rb file
#From this you should be able to build associations to retrieve by user, by ledger item, ledge line item
Elizabeth McGurty
Aug 20, 2015, 11:04:04 AM8/20/15
to Ruby on Rails: Talk
Thanks Colin and Walter for contribution.... Liz
Elizabeth McGurty
Aug 20, 2015, 11:07:43 AM8/20/15
to Ruby on Rails: Talk
Forgot:
class User < ActiveRecord::Base
has_many :user_transaction
end
class User < ActiveRecord::Base
has_many :user_transaction
end
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