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myobie/gist:22382

Created Nov 5, 2008
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### The controller
def index
@products = Product.all(:order => [:model_number, :model_name])
display @products
end
### The model
belongs_to :manufacturer
belongs_to :category
belongs_to :group
belongs_to :gsa_contract
belongs_to :geographic_origin
belongs_to :sin_number
has n, :photos
### The view
%table#products.products{ :cellpadding => 3, :cellspacing=>0 }
%thead
%tr
- ['Image', 'Model Number', 'Name', 'Price', 'Cur', "Man", "Group", "Geo"].each do |table_header|
%th= table_header
%tbody
- @products.each do |product|
%tr[product]
%td.image
%img{ :src=> product.photo.url(:tiny), :width => 30, :height => 30 }
%td.model_number= product.model_number #, url(:product, :id => product.id)
%td.model_name= product.model_name
%td.price_range= product.price_range
%td.currency= product.currency
%td.manufacturer= product.manufacturer ? product.manufacturer.title : "None"
%td.group= product.group ? product.group.title : "None"
%td.geo= product.geographic_origin ? product.geographic_origin.title : "None"
### Explanation
#
# What happens is this (shortened to make it easier to read):
#
# ~ SELECT `id`, `model_number`, `model_name`, ... FROM `products` ORDER BY `model_number`, `model_name`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (64, 721, ...)
# ~ SELECT `id`, `title`, `gsa_discount`, `gsa_markup`, `net_discount`, `ecommerce_discount`, `created_at`, `updated_at` FROM `manufacturers` WHERE (`id` IN (1, 2, 6, 10, 13, 11, 5, 12)) ORDER BY `id`
# ~ SELECT `id`, `title`, `created_at`, `updated_at` FROM `groups` WHERE (`id` IN (3, 110, ...)) ORDER BY `id`
# ~ SELECT `id`, `title`, `created_at`, `updated_at` FROM `geographic_origins` WHERE (`id` IN (1, 4, ...)) ORDER BY `id`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (325)) ORDER BY `id`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (157)) ORDER BY `id`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (325)) ORDER BY `id`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (176)) ORDER BY `id`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (325)) ORDER BY `id`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (172)) ORDER BY `id`
# ~ SELECT `id`, `filename`, `content_type`, `file_size`, `drawing`, `thumbnailed`, `original_url`, `product_id` FROM `photos` WHERE (`product_id` IN (325)) ORDER BY `id`
# ... (and so on)
#
# You can see it's loading each image row again, instead of using what it got in the huge load it did with all the id's. What is really strange is that 325 loads every other time seperately.
#
# This is actually looping over aroun 753 records, but it only loads 47 individual images (which includes the 325 every other time).
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