multi-dimentional array

J

Joan Gu

I need to insert Broad Category value and Topics value into a table,
doing something like this (where 'Police, Crime, Drugs' are topics
values and 'Crime & Law Enforcement' is broad category value):

obj1 = 'Police, Crime, Drugs'
obj1 = obj1.split(',').map do |tag_name|
execute "insert into tags (name,counter) values
('#{tag_name.strip.downcase}', 0)"
t = Tag.find_by_name(tag_name.strip.downcase)
tt = t.tag_with('Crime & Law Enforcement')
end

When it comes with multiple broad categories and topics, I want to build
an array in a form like
[['Police, Crime, Drugs','Crime & Law Enforcement'],['Fire, Emergency
Services','Emergency Management'], ['Schools, Colleges,
Libraries','Education'],...]
to iterate the executions. I worked for quite some hours, but still
can't make it work. Can someone help?

Joan
 
D

David A. Black

Hi --

I need to insert Broad Category value and Topics value into a table,
doing something like this (where 'Police, Crime, Drugs' are topics
values and 'Crime & Law Enforcement' is broad category value):

obj1 = 'Police, Crime, Drugs'
obj1 = obj1.split(',').map do |tag_name|
execute "insert into tags (name,counter) values
('#{tag_name.strip.downcase}', 0)"
t = Tag.find_by_name(tag_name.strip.downcase)
tt = t.tag_with('Crime & Law Enforcement')
end

When it comes with multiple broad categories and topics, I want to build
an array in a form like
[['Police, Crime, Drugs','Crime & Law Enforcement'],['Fire, Emergency
Services','Emergency Management'], ['Schools, Colleges,
Libraries','Education'],...]
to iterate the executions. I worked for quite some hours, but still
can't make it work. Can someone help?

I think you want something like this:

tagsets = [['Police, Crime, Drugs','Crime & Law Enforcement'],
['Fire, Emergency Services','Emergency Management'],
['Schools, Colleges, Libraries','Education']]

tagsets.each do |tagset|
broad, topic = tagset
broads = broad.split(",").map {|s| s.strip }
puts "Broad: #{broads.join("; ")}\n\tTopic: #{topic}" # etc.
end


David

--
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ADVANCING WITH RAILS April 14-17 New York City
INTRO TO RAILS June 9-12 Berlin
ADVANCING WITH RAILS June 16-19 Berlin
See http://www.rubypal.com for details and updates!
 
P

Paul Mckibbin

Joan said:
I need to insert Broad Category value and Topics value into a table,
doing something like this (where 'Police, Crime, Drugs' are topics
values and 'Crime & Law Enforcement' is broad category value):

How about using a hash with arrays underneath?

Something like:


category_hash={}
cat1 = 'Crime & Law Enforcement'
cat2 = 'Emergency Management'
obj1 = 'Police, Crime, Drugs'
obj2 = 'Fire, Emergency Services'

category_hash[cat1]= obj1.split(",").map {|s| s.strip}
category_hash[cat2]= obj2.split(",").map {|s| s.strip}

You can then add new items like this:

category_hash[cat1] << 'New Crime related item'

puts category_hash.inspect
#=>{"Emergency Management"=>["Fire", "Emergency Services"], "Crime & Law
Enforcement"=>["Police", "Crime", "Drugs", "New Crime related item"]}

and you can then iterate through categories and within each category
through the items.

Mac
 
J

Joan Gu

To Mac,

Your solution sounds like a good approach, but may not fit in my
situation, since I am actually writing Rails migration file, which is
more like a 'one time deal'. :)

Thanks for your help.
Joan
 
T

Todd Benson

I need to insert Broad Category value and Topics value into a table,
doing something like this (where 'Police, Crime, Drugs' are topics
values and 'Crime & Law Enforcement' is broad category value):

obj1 = 'Police, Crime, Drugs'
obj1 = obj1.split(',').map do |tag_name|
execute "insert into tags (name,counter) values
('#{tag_name.strip.downcase}', 0)"
t = Tag.find_by_name(tag_name.strip.downcase)
tt = t.tag_with('Crime & Law Enforcement')
end

When it comes with multiple broad categories and topics, I want to build
an array in a form like
[['Police, Crime, Drugs','Crime & Law Enforcement'],['Fire, Emergency
Services','Emergency Management'], ['Schools, Colleges,
Libraries','Education'],...]
to iterate the executions. I worked for quite some hours, but still
can't make it work. Can someone help?

Joan

Can't help you with migrations, but what's your relationship model?
Is it one to one and that's why you want an array like that? Is it
one many (which is what I'd suspect)? Is it many to many?

You did say "a" table. Somehow, that doesn't seem to correctly fit your model.

Todd
 
P

Paul Mckibbin

Can't help you with migrations, but what's your relationship model?
Is it one to one and that's why you want an array like that? Is it
one many (which is what I'd suspect)? Is it many to many?

You did say "a" table. Somehow, that doesn't seem to correctly fit your
model.

Todd
Seems to me that could even be n-n, since a category like "Police
Academy" could fit into two topics. :)

Mac
 

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