activerecord-import/lib/activerecord-import/import.rb

390 lines
16 KiB
Ruby

require "ostruct"
module ActiveRecord::Import::ConnectionAdapters ; end
module ActiveRecord::Import #:nodoc:
class Result < Struct.new(:failed_instances, :num_inserts, :last_inserted_id)
end
module ImportSupport #:nodoc:
def supports_import? #:nodoc:
true
end
end
module OnDuplicateKeyUpdateSupport #:nodoc:
def supports_on_duplicate_key_update? #:nodoc:
true
end
end
class MissingColumnError < StandardError
def initialize(name, index)
super "Missing column for value <#{name}> at index #{index}"
end
end
end
class ActiveRecord::Base
class << self
# use tz as set in ActiveRecord::Base
tproc = lambda do
ActiveRecord::Base.default_timezone == :utc ? Time.now.utc : Time.now
end
AREXT_RAILS_COLUMNS = {
:create => { "created_on" => tproc ,
"created_at" => tproc },
:update => { "updated_on" => tproc ,
"updated_at" => tproc }
}
AREXT_RAILS_COLUMN_NAMES = AREXT_RAILS_COLUMNS[:create].keys + AREXT_RAILS_COLUMNS[:update].keys
# Returns true if the current database connection adapter
# supports import functionality, otherwise returns false.
def supports_import?
connection.supports_import?
rescue NoMethodError
false
end
# Returns true if the current database connection adapter
# supports on duplicate key update functionality, otherwise
# returns false.
def supports_on_duplicate_key_update?
connection.supports_on_duplicate_key_update?
rescue NoMethodError
false
end
# Imports a collection of values to the database.
#
# This is more efficient than using ActiveRecord::Base#create or
# ActiveRecord::Base#save multiple times. This method works well if
# you want to create more than one record at a time and do not care
# about having ActiveRecord objects returned for each record
# inserted.
#
# This can be used with or without validations. It does not utilize
# the ActiveRecord::Callbacks during creation/modification while
# performing the import.
#
# == Usage
# Model.import array_of_models
# Model.import column_names, array_of_values
# Model.import column_names, array_of_values, options
#
# ==== Model.import array_of_models
#
# With this form you can call _import_ passing in an array of model
# objects that you want updated.
#
# ==== Model.import column_names, array_of_values
#
# The first parameter +column_names+ is an array of symbols or
# strings which specify the columns that you want to update.
#
# The second parameter, +array_of_values+, is an array of
# arrays. Each subarray is a single set of values for a new
# record. The order of values in each subarray should match up to
# the order of the +column_names+.
#
# ==== Model.import column_names, array_of_values, options
#
# The first two parameters are the same as the above form. The third
# parameter, +options+, is a hash. This is optional. Please see
# below for what +options+ are available.
#
# == Options
# * +validate+ - true|false, tells import whether or not to use \
# ActiveRecord validations. Validations are enforced by default.
# * +on_duplicate_key_update+ - an Array or Hash, tells import to \
# use MySQL's ON DUPLICATE KEY UPDATE ability. See On Duplicate\
# Key Update below.
# * +synchronize+ - an array of ActiveRecord instances for the model
# that you are currently importing data into. This synchronizes
# existing model instances in memory with updates from the import.
# * +timestamps+ - true|false, tells import to not add timestamps \
# (if false) even if record timestamps is disabled in ActiveRecord::Base
#
# == Examples
# class BlogPost < ActiveRecord::Base ; end
#
# # Example using array of model objects
# posts = [ BlogPost.new :author_name=>'Zach Dennis', :title=>'AREXT',
# BlogPost.new :author_name=>'Zach Dennis', :title=>'AREXT2',
# BlogPost.new :author_name=>'Zach Dennis', :title=>'AREXT3' ]
# BlogPost.import posts
#
# # Example using column_names and array_of_values
# columns = [ :author_name, :title ]
# values = [ [ 'zdennis', 'test post' ], [ 'jdoe', 'another test post' ] ]
# BlogPost.import columns, values
#
# # Example using column_names, array_of_value and options
# columns = [ :author_name, :title ]
# values = [ [ 'zdennis', 'test post' ], [ 'jdoe', 'another test post' ] ]
# BlogPost.import( columns, values, :validate => false )
#
# # Example synchronizing existing instances in memory
# post = BlogPost.find_by_author_name( 'zdennis' )
# puts post.author_name # => 'zdennis'
# columns = [ :author_name, :title ]
# values = [ [ 'yoda', 'test post' ] ]
# BlogPost.import posts, :synchronize=>[ post ]
# puts post.author_name # => 'yoda'
#
# # Example synchronizing unsaved/new instances in memory by using a uniqued imported field
# posts = [BlogPost.new(:title => "Foo"), BlogPost.new(:title => "Bar")]
# BlogPost.import posts, :synchronize => posts, :synchronize_keys => [:title]
# puts posts.first.persisted? # => true
#
# == On Duplicate Key Update (MySQL only)
#
# The :on_duplicate_key_update option can be either an Array or a Hash.
#
# ==== Using an Array
#
# The :on_duplicate_key_update option can be an array of column
# names. The column names are the only fields that are updated if
# a duplicate record is found. Below is an example:
#
# BlogPost.import columns, values, :on_duplicate_key_update=>[ :date_modified, :content, :author ]
#
# ==== Using A Hash
#
# The :on_duplicate_key_update option can be a hash of column name
# to model attribute name mappings. This gives you finer grained
# control over what fields are updated with what attributes on your
# model. Below is an example:
#
# BlogPost.import columns, attributes, :on_duplicate_key_update=>{ :title => :title }
#
# = Returns
# This returns an object which responds to +failed_instances+, +num_inserts+, +last_inserted_id+.
# * failed_instances - an array of objects that fails validation and were not committed to the database. An empty array if no validation is performed.
# * num_inserts - the number of insert statements it took to import the data.
# * last_inserted_id - the last inserted id. Should be the id of the latest inserted row.
def import( *args )
options = { :validate=>true, :timestamps=>true }
options.merge!( args.pop ) if args.last.is_a? Hash
is_validating = options.delete( :validate )
# assume array of model objects
if args.last.is_a?( Array ) and args.last.first.is_a? ActiveRecord::Base
if args.length == 2
models = args.last
column_names = args.first
else
models = args.first
column_names = self.column_names.dup
end
array_of_attributes = models.map do |model|
# this next line breaks sqlite.so with a segmentation fault
# if model.new_record? || options[:on_duplicate_key_update]
column_names.map do |name|
model.send( "#{name}_before_type_cast" )
end
# end
end
# supports empty array
elsif args.last.is_a?( Array ) and args.last.empty?
return ActiveRecord::Import::Result.new([], 0, nil) if args.last.empty?
# supports 2-element array and array
elsif args.size == 2 and args.first.is_a?( Array ) and args.last.is_a?( Array )
column_names, array_of_attributes = args
else
raise ArgumentError.new( "Invalid arguments!" )
end
# dup the passed in array so we don't modify it unintentionally
array_of_attributes = array_of_attributes.dup
# Force the primary key col into the insert if it's not
# on the list and we are using a sequence and stuff a nil
# value for it into each row so the sequencer will fire later
if !column_names.include?(primary_key) && sequence_name && connection.prefetch_primary_key?
column_names << primary_key
array_of_attributes.each { |a| a << nil }
end
# record timestamps unless disabled in ActiveRecord::Base
if record_timestamps && options.delete( :timestamps )
add_special_rails_stamps column_names, array_of_attributes, options
end
return_obj = if is_validating
import_with_validations( column_names, array_of_attributes, options )
else
[num_inserts, last_inserted_id] = import_without_validations_or_callbacks( column_names, array_of_attributes, options )
ActiveRecord::Import::Result.new([], num_inserts, last_inserted_id)
end
if options[:synchronize]
sync_keys = options[:synchronize_keys] || [self.primary_key]
synchronize( options[:synchronize], sync_keys)
end
return_obj.num_inserts = 0 if return_obj.num_inserts.nil?
return_obj
end
# TODO import_from_table needs to be implemented.
def import_from_table( options ) # :nodoc:
end
# Imports the passed in +column_names+ and +array_of_attributes+
# given the passed in +options+ Hash with validations. Returns an
# object with the methods +failed_instances+ and +num_inserts+.
# +failed_instances+ is an array of instances that failed validations.
# +num_inserts+ is the number of inserts it took to import the data. See
# ActiveRecord::Base.import for more information on
# +column_names+, +array_of_attributes+ and +options+.
def import_with_validations( column_names, array_of_attributes, options={} )
failed_instances = []
# create instances for each of our column/value sets
arr = validations_array_for_column_names_and_attributes( column_names, array_of_attributes )
# keep track of the instance and the position it is currently at. if this fails
# validation we'll use the index to remove it from the array_of_attributes
arr.each_with_index do |hsh,i|
instance = new do |model|
hsh.each_pair{ |k,v| model.send("#{k}=", v) }
end
if not instance.valid?
array_of_attributes[ i ] = nil
failed_instances << instance
end
end
array_of_attributes.compact!
num_inserts, last_inserted_id = if array_of_attributes.empty? || options[:all_or_none] && failed_instances.any?
[0, nil]
else
import_without_validations_or_callbacks( column_names, array_of_attributes, options )
end
ActiveRecord::Import::Result.new(failed_instances, num_inserts, last_inserted_id)
end
# Imports the passed in +column_names+ and +array_of_attributes+
# given the passed in +options+ Hash. This will return the number
# of insert operations it took to create these records without
# validations or callbacks. See ActiveRecord::Base.import for more
# information on +column_names+, +array_of_attributes_ and
# +options+.
def import_without_validations_or_callbacks( column_names, array_of_attributes, options={} )
number_inserted, last_inserted_id = 0, nil
scope_columns, scope_values = scope_attributes.to_a.transpose
unless scope_columns.blank?
column_names.concat scope_columns
array_of_attributes.each { |a| a.concat scope_values }
end
columns = column_names.each_with_index.map do |name, i|
column = columns_hash[name.to_s]
raise ActiveRecord::Import::MissingColumnError.new(name.to_s, i) if column.nil?
column
end
columns_sql = "(#{column_names.map{|name| connection.quote_column_name(name) }.join(',')})"
insert_sql = "INSERT #{options[:ignore] ? 'IGNORE ':''}INTO #{quoted_table_name} #{columns_sql} VALUES "
values_sql = values_sql_for_columns_and_attributes(columns, array_of_attributes)
if not supports_import?
number_inserted = 0
values_sql.each do |values|
connection.execute(insert_sql + values)
number_inserted += 1
end
else
# generate the sql
post_sql_statements = connection.post_sql_statements( quoted_table_name, options )
# perform the inserts
number_inserted, last_inserted_id = connection.insert_many( [ insert_sql, post_sql_statements ].flatten,
values_sql,
"#{self.class.name} Create Many Without Validations Or Callbacks" )
end
[number_inserted, last_inserted_id]
end
private
# Returns SQL the VALUES for an INSERT statement given the passed in +columns+
# and +array_of_attributes+.
def values_sql_for_columns_and_attributes(columns, array_of_attributes) # :nodoc:
# connection gets called a *lot* in this high intensity loop.
# Reuse the same one w/in the loop, otherwise it would keep being re-retreived (= lots of time for large imports)
connection_memo = connection
array_of_attributes.map do |arr|
my_values = arr.each_with_index.map do |val,j|
column = columns[j]
# be sure to query sequence_name *last*, only if cheaper tests fail, because it's costly
if val.nil? && column.name == primary_key && !sequence_name.blank?
connection_memo.next_value_for_sequence(sequence_name)
else
if serialized_attributes.include?(column.name)
connection_memo.quote(serialized_attributes[column.name].dump(val), column)
else
connection_memo.quote(val, column)
end
end
end
"(#{my_values.join(',')})"
end
end
def add_special_rails_stamps( column_names, array_of_attributes, options )
AREXT_RAILS_COLUMNS[:create].each_pair do |key, blk|
if self.column_names.include?(key)
value = blk.call
if index=column_names.index(key)
# replace every instance of the array of attributes with our value
array_of_attributes.each{ |arr| arr[index] = value }
else
column_names << key
array_of_attributes.each { |arr| arr << value }
end
end
end
AREXT_RAILS_COLUMNS[:update].each_pair do |key, blk|
if self.column_names.include?(key)
value = blk.call
if index=column_names.index(key)
# replace every instance of the array of attributes with our value
array_of_attributes.each{ |arr| arr[index] = value }
else
column_names << key
array_of_attributes.each { |arr| arr << value }
end
if supports_on_duplicate_key_update?
if options[:on_duplicate_key_update]
options[:on_duplicate_key_update] << key.to_sym if options[:on_duplicate_key_update].is_a?(Array)
options[:on_duplicate_key_update][key.to_sym] = key.to_sym if options[:on_duplicate_key_update].is_a?(Hash)
else
options[:on_duplicate_key_update] = [ key.to_sym ]
end
end
end
end
end
# Returns an Array of Hashes for the passed in +column_names+ and +array_of_attributes+.
def validations_array_for_column_names_and_attributes( column_names, array_of_attributes ) # :nodoc:
array_of_attributes.map do |attributes|
Hash[attributes.each_with_index.map {|attr, c| [column_names[c], attr] }]
end
end
end
end