Export nested entities to CSV file
I have a rails app with some nested data that I'd like to export as a CSV file
The models look like:
class ContainerRecord < ActiveRecord::Base
has_many :child_records
and
class ChildRecord < ActiveRecord::Base
belongs_to :container_record
I'd like to be able to export a CSV file with each ContainerRecord on a row with its information in the first few columns and a value from each ChildRecord in the remaining columns.
I can't guarantee the number of ChildRecords associated with each ContainerRecord and I don't care if I have a different number of non-null columns for each row.
I've attempted to use FasterCSV, but I get all of the data for the child records shoved into one column rather than a column for each.
Is thi开发者_开发百科s something that I can do with FasterCSV? If not, what method can I use to accomplish my goal?
Not sure about FasterCSV but a quick & dirty solution could be:
class ParentClass < AR::Base
has_many :children
def self.csv
all.map do |object|
( object.attributes.values + object.children.map(&:child_field) ).flatten.join(',')
end.join("\n")
end
end
Replacing "child_field" with the field you want to take from your child model of course.
I ended up finding a nice tutorial on csv_builder that let me do exactly what I wanted to do with minimal effort and allowed me to stick a little more closely to the MVC architecture.
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