在我们的Rails 3.2.13应用程序（Heroku中的Ruby 2.0.0 + Postgres）中，我们经常从API中检索大量订单数据，然后我们需要更新或创建数据库中的每个订单，如以及协会。单个订单创建/更新自身加上约。 10-15个关联对象，我们一次最多可以导入500个订单。
以下代码有效，但问题是速度方面效率不高。创建/更新500条记录大约需要1分钟，生成6500多个数据库查询！
def add_details(shop, shopify_orders)
shopify_orders.each do |shopify_order|
order = Order.where(:order_id => shopify_order.id.to_s, :shop_id => shop.id).first_or_create
order.update_details(order,shopify_order,shop) #This calls update_attributes for the Order
ShippingLine.add_details(order, shopify_order.shipping_lines)
LineItem.add_details(order, shopify_order.line_items)
Taxline.add_details(order, shopify_order.tax_lines)
Fulfillment.add_details(order, shopify_order.fulfillments)
Note.add_details(order, shopify_order.note_attributes)
Discount.add_details(order, shopify_order.discount_codes)
billing_address = shopify_order.billing_address rescue nil
if !billing_address.blank?
BillingAddress.add_details(order, billing_address)
end
shipping_address = shopify_order.shipping_address rescue nil
if !shipping_address.blank?
ShippingAddress.add_details(order, shipping_address)
end
payment_details = shopify_order.payment_details rescue nil
if !payment_details.blank?
PaymentDetail.add_details(order, payment_details)
end
end
end
def update_details(order,shopify_order,shop)
order.update_attributes(
:order_name => shopify_order.name,
:order_created_at => shopify_order.created_at,
:order_updated_at => shopify_order.updated_at,
:status => Order.get_status(shopify_order),
:payment_status => shopify_order.financial_status,
:fulfillment_status => Order.get_fulfillment_status(shopify_order),
:payment_method => shopify_order.processing_method,
:gateway => shopify_order.gateway,
:currency => shopify_order.currency,
:subtotal_price => shopify_order.subtotal_price,
:subtotal_tax => shopify_order.total_tax,
:total_discounts => shopify_order.total_discounts,
:total_line_items_price => shopify_order.total_line_items_price,
:total_price => shopify_order.total_price,
:total_tax => shopify_order.total_tax,
:total_weight => shopify_order.total_weight,
:taxes_included => shopify_order.taxes_included,
:shop_id => shop.id,
:email => shopify_order.email,
:order_note => shopify_order.note
)
end
正如您所看到的，我们循环遍历每个订单，查明它是否存在（然后加载现有订单或创建新订单），然后调用update_attributes以传递订单的详细信息。之后，我们创建或更新每个关联。每个相关模型看起来都非常相似：
class << self
def add_details(order, tax_lines)
tax_lines.each do |shopify_tax_line|
taxline = Taxline.find_or_create_by_order_id(:order_id => order.id)
taxline.update_details(shopify_tax_line)
end
end
end
def update_details(tax_line)
self.update_attributes(:price => tax_line.price, :rate => tax_line.rate, :title => tax_line.title)
end
我已经查看了activerecord-import gem，但遗憾的是它似乎更倾向于批量创建记录而不是我们也需要更新。
这可以改善性能的最佳方法是什么？
许多人提前感谢。
更新
我想出了一个小小的改进，它基本上删除了更新新创建的订单的调用（每个订单少一个查询）。
def add_details(shop, shopify_orders)
shopify_orders.each do |shopify_order|
values = {:order_id => shopify_order.id.to_s, :shop_id => shop.id,
:order_name => shopify_order.name,
:order_created_at => shopify_order.created_at,
:order_updated_at => shopify_order.updated_at,
:status => Order.get_status(shopify_order),
:payment_status => shopify_order.financial_status,
:fulfillment_status => Order.get_fulfillment_status(shopify_order),
:payment_method => shopify_order.processing_method,
:gateway => shopify_order.gateway,
:currency => shopify_order.currency,
:subtotal_price => shopify_order.subtotal_price,
:subtotal_tax => shopify_order.total_tax,
:total_discounts => shopify_order.total_discounts,
:total_line_items_price => shopify_order.total_line_items_price,
:total_price => shopify_order.total_price,
:total_tax => shopify_order.total_tax,
:total_weight => shopify_order.total_weight,
:taxes_included => shopify_order.taxes_included,
:email => shopify_order.email,
:order_note => shopify_order.note}
get_order = Order.where(:order_id => shopify_order.id.to_s, :shop_id => shop.id)
if get_order.blank?
order = Order.create(values)
else
order = get_order.first
order.update_attributes(values)
end
ShippingLine.add_details(order, shopify_order.shipping_lines)
LineItem.add_details(order, shopify_order.line_items)
Taxline.add_details(order, shopify_order.tax_lines)
Fulfillment.add_details(order, shopify_order.fulfillments)
Note.add_details(order, shopify_order.note_attributes)
Discount.add_details(order, shopify_order.discount_codes)
billing_address = shopify_order.billing_address rescue nil
if !billing_address.blank?
BillingAddress.add_details(order, billing_address)
end
shipping_address = shopify_order.shipping_address rescue nil
if !shipping_address.blank?
ShippingAddress.add_details(order, shipping_address)
end
payment_details = shopify_order.payment_details rescue nil
if !payment_details.blank?
PaymentDetail.add_details(order, payment_details)
end
end
end
以及相关对象：
class << self
def add_details(order, tax_lines)
tax_lines.each do |shopify_tax_line|
values = {:order_id => order.id,
:price => tax_line.price,
:rate => tax_line.rate,
:title => tax_line.title}
get_taxline = Taxline.where(:order_id => order.id)
if get_taxline.blank?
taxline = Taxline.create(values)
else
taxline = get_taxline.first
taxline.update_attributes(values)
end
end
end
end
有更好的建议吗？
答案 0 :(得分：6)
尝试将整个代码包装到单个数据库事务中。由于你是Heroku，它将成为Postgres的底端。通过这么多更新语句，您可以通过一次性处理它们来获益，因此您的代码执行得更快，基本上只留下一个＆＃34;队列＆＃34;在Postgres端运行6500个语句，因为服务器能够将它们出列。根据底端，您可能需要进行更小的交易 - 但即使每次交易100（然后关闭并重新打开交易）也会大大提高到Pg的吞吐量。
http://api.rubyonrails.org/classes/ActiveRecord/Transactions/ClassMethods.html http://www.postgresql.org/docs/9.2/static/sql-set-transaction.html
所以在第2行之前你要添加如下内容：
def add_details(shop, shopify_orders)
Order.transaction do
shopify_orders.each do |shopify_order|
然后在你方法的最后添加另一个结尾：
if !payment_details.blank?
PaymentDetail.add_details(order, payment_details)
end
end //shopify_orders.each..
end //Order.transaction..
end //method
答案 1 :(得分：1)
你可以像这样修补ActiveRecord：
class ActiveRecord::Base
#http://stackoverflow.com/questions/15317837/bulk-insert-records-into-active-record-table?lq=1
#https://gist.github.com/jackrg/76ade1724bd816292e4e
# "UPDATE THIS SET <list_of_column_assignments> FROM <table_name> THIS JOIN (VALUES (<csv1>, <csv2>,...) VALS ( <column_names> ) ON <list_of_primary_keys_comparison>"
def self.bulk_update(record_list)
pk = self.primary_key
raise "primary_key not found" unless pk.present?
raise "record_list not an Array of Hashes" unless record_list.is_a?(Array) && record_list.all? {|rec| rec.is_a? Hash }
return nil if record_list.empty?
result = nil
#test if every hash has primary keys, so we can JOIN
record_list.each { |r| raise "Primary Keys '#{self.primary_key.to_s}' not found on record: #{r}" unless hasAllPKs?(r) }
#list of primary keys comparison
pk_comparison_array = []
if (pk).is_a?(Array)
pk.each {|thiskey| pk_comparison_array << "THIS.#{thiskey} = VALS.#{thiskey}" }
else
pk_comparison_array << "THIS.#{pk} = VALS.#{pk}"
end
pk_comparison = pk_comparison_array.join(' AND ')
#SQL
(1..record_list.count).step(1000).each do |start|
key_list, value_list = convert_record_list(record_list[start-1..start+999])
#csv values
csv_vals = value_list.map {|v| "(#{v.join(", ")})" }.join(", ")
#column names
column_names = key_list.join(", ")
#list of columns assignments
columns_assign_array = []
key_list.each {|col|
unless inPK?(col)
columns_assign_array << "THIS.#{col} = VALS.#{col}"
end }
columns_assign = columns_assign_array.join(', ')
sql = "UPDATE THIS SET #{columns_assign} FROM #{self.table_name} THIS JOIN ( VALUES #{csv_vals} ) VALS ( #{column_names} ) ON ( #{pk_comparison} )"
result = self.connection.execute(sql)
return result if result<0
end
return result
end
def self.inPK?(str)
pk = self.primary_key
test = str.to_s
if pk.is_a?(Array)
(pk.include?(test))
else
(pk==test)
end
end
#test if given hash has primary keys included as hash keys and those keys are not empty
def self.hasAllPKs?(hash)
h = hash.stringify_keys
pk = self.primary_key
if pk.is_a?(Array)
(pk.all? {|k| h.key?(k) and h[k].present? })
else
h.key?(pk) and h[pk].present?
end
end
def self.convert_record_list(record_list)
# Build the list of keys
key_list = record_list.map(&:keys).flatten.map(&:to_s).uniq.sort
value_list = record_list.map do |rec|
list = []
key_list.each {|key| list << ActiveRecord::Base.connection.quote(rec[key] || rec[key.to_sym]) }
list
end
# If table has standard timestamps and they're not in the record list then add them to the record list
time = ActiveRecord::Base.connection.quote(Time.now)
for field_name in %w(created_at updated_at)
if self.column_names.include?(field_name) && !(key_list.include?(field_name))
key_list << field_name
value_list.each {|rec| rec << time }
end
end
return [key_list, value_list]
end
end
然后，您可以生成包含模型属性（包括其主键）的哈希数组，并执行以下操作：
ActiveRecord::Base.transaction do
Model.bulk_update [ {attr1: val1, attr2: val2,...}, {attr1: val1, attr2: val2,...}, ... ]
end
它将是一个没有Rails回调和验证的SQL命令。
答案 2 :(得分：0)
对于PostgreSQL，上述方法无法解决几个问题：
在一个简单的“UPDATE”命令中，你没有在VALUES表中得到相同的“自由”强制转换，所以你必须这样投出日期/时间戳值（#val_cast这样做）。 / p>
class ActiveRecord::Base
def self.update!(record_list)
raise ArgumentError "record_list not an Array of Hashes" unless record_list.is_a?(Array) && record_list.all? {|rec| rec.is_a? Hash }
return record_list if record_list.empty?
(1..record_list.count).step(1000).each do |start|
field_list, value_list = convert_record_list(record_list[start-1..start+999])
key_field = self.primary_key
non_key_fields = field_list - [%Q["#{self.primary_key}"], %Q["created_at"]]
columns_assign = non_key_fields.map {|field| "#{field} = #{val_cast(field)}"}.join(",")
value_table = value_list.map {|row| "(#{row.join(", ")})" }.join(", ")
sql = "UPDATE #{table_name} AS this SET #{columns_assign} FROM (VALUES #{value_table}) vals (#{field_list.join(", ")}) WHERE this.#{key_field} = vals.#{key_field}"
self.connection.update_sql(sql)
end
return record_list
end
def self.val_cast(field)
field = field.gsub('"', '')
if (column = columns.find{|c| c.name == field }).sql_type =~ /time|date/
"cast (vals.#{field} as #{column.sql_type})"
else
"vals.#{field}"
end
end
def self.convert_record_list(record_list)
# Build the list of fields
field_list = record_list.map(&:keys).flatten.map(&:to_s).uniq.sort
value_list = record_list.map do |rec|
list = []
field_list.each {|field| list << ActiveRecord::Base.connection.quote(rec[field] || rec[field.to_sym]) }
list
end
# If table has standard timestamps and they're not in the record list then add them to the record list
time = ActiveRecord::Base.connection.quote(Time.now)
for field_name in %w(created_at updated_at)
if self.column_names.include?(field_name) && !(field_list.include?(field_name))
field_list << field_name
value_list.each {|rec| rec << time }
end
end
field_list.map! {|field| %Q["#{field}"] }
return [field_list, value_list]
end
end