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-rw-r--r--activerecord/lib/active_record/relation.rb106
1 files changed, 71 insertions, 35 deletions
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 4d24654015..d37471e9ad 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -10,7 +10,7 @@ module ActiveRecord
:extending]
SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reordering,
- :reverse_order, :distinct, :create_with]
+ :reverse_order, :distinct, :create_with, :uniq]
VALUE_METHODS = MULTI_VALUE_METHODS + SINGLE_VALUE_METHODS
@@ -26,7 +26,6 @@ module ActiveRecord
@klass = klass
@table = table
@values = values
- @implicit_readonly = nil
@loaded = false
@default_scoped = false
end
@@ -39,7 +38,7 @@ module ActiveRecord
reset
end
- def insert(values)
+ def insert(values) # :nodoc:
primary_key_value = nil
if primary_key && Hash === values
@@ -56,16 +55,7 @@ module ActiveRecord
im = arel.create_insert
im.into @table
- conn = @klass.connection
-
- substitutes = values.sort_by { |arel_attr,_| arel_attr.name }
- binds = substitutes.map do |arel_attr, value|
- [@klass.columns_hash[arel_attr.name], value]
- end
-
- substitutes.each_with_index do |tuple, i|
- tuple[1] = conn.substitute_at(binds[i][0], i)
- end
+ substitutes, binds = substitute_values values
if values.empty? # empty insert
im.values = Arel.sql(connection.empty_insert_statement_value)
@@ -73,7 +63,7 @@ module ActiveRecord
im.insert substitutes
end
- conn.insert(
+ @klass.connection.insert(
im,
'SQL',
primary_key,
@@ -82,6 +72,29 @@ module ActiveRecord
binds)
end
+ def update_record(values, id, id_was) # :nodoc:
+ substitutes, binds = substitute_values values
+ um = @klass.unscoped.where(@klass.arel_table[@klass.primary_key].eq(id_was || id)).arel.compile_update(substitutes)
+
+ @klass.connection.update(
+ um,
+ 'SQL',
+ binds)
+ end
+
+ def substitute_values(values) # :nodoc:
+ substitutes = values.sort_by { |arel_attr,_| arel_attr.name }
+ binds = substitutes.map do |arel_attr, value|
+ [@klass.columns_hash[arel_attr.name], value]
+ end
+
+ substitutes.each_with_index do |tuple, i|
+ tuple[1] = @klass.connection.substitute_at(binds[i][0], i)
+ end
+
+ [substitutes, binds]
+ end
+
# Initializes new record from relation while maintaining the current
# scope.
#
@@ -141,34 +154,58 @@ module ActiveRecord
first || new(attributes, &block)
end
- # Finds the first record with the given attributes, or creates a record with the attributes
- # if one is not found.
+ # Finds the first record with the given attributes, or creates a record
+ # with the attributes if one is not found:
#
- # ==== Examples
- # # Find the first user named Penélope or create a new one.
+ # # Find the first user named "Penélope" or create a new one.
# User.find_or_create_by(first_name: 'Penélope')
- # # => <User id: 1, first_name: 'Penélope', last_name: nil>
+ # # => #<User id: 1, first_name: "Penélope", last_name: nil>
#
- # # Find the first user named Penélope or create a new one.
+ # # Find the first user named "Penélope" or create a new one.
# # We already have one so the existing record will be returned.
# User.find_or_create_by(first_name: 'Penélope')
- # # => <User id: 1, first_name: 'Penélope', last_name: nil>
+ # # => #<User id: 1, first_name: "Penélope", last_name: nil>
#
- # # Find the first user named Scarlett or create a new one with a particular last name.
+ # # Find the first user named "Scarlett" or create a new one with
+ # # a particular last name.
# User.create_with(last_name: 'Johansson').find_or_create_by(first_name: 'Scarlett')
- # # => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'>
+ # # => #<User id: 2, first_name: "Scarlett", last_name: "Johansson">
#
- # # Find the first user named Scarlett or create a new one with a different last name.
- # # We already have one so the existing record will be returned.
+ # This method accepts a block, which is passed down to +create+. The last example
+ # above can be alternatively written this way:
+ #
+ # # Find the first user named "Scarlett" or create a new one with a
+ # # different last name.
# User.find_or_create_by(first_name: 'Scarlett') do |user|
- # user.last_name = "O'Hara"
+ # user.last_name = 'Johansson'
# end
- # # => <User id: 2, first_name: 'Scarlett', last_name: 'Johansson'>
+ # # => #<User id: 2, first_name: "Scarlett", last_name: "Johansson">
+ #
+ # This method always returns a record, but if creation was attempted and
+ # failed due to validation errors it won't be persisted, you get what
+ # +create+ returns in such situation.
+ #
+ # Please note *this method is not atomic*, it runs first a SELECT, and if
+ # there are no results an INSERT is attempted. If there are other threads
+ # or processes there is a race condition between both calls and it could
+ # be the case that you end up with two similar records.
+ #
+ # Whether that is a problem or not depends on the logic of the
+ # application, but in the particular case in which rows have a UNIQUE
+ # constraint an exception may be raised, just retry:
+ #
+ # begin
+ # CreditAccount.find_or_create_by(user_id: user.id)
+ # rescue ActiveRecord::RecordNotUnique
+ # retry
+ # end
+ #
def find_or_create_by(attributes, &block)
find_by(attributes) || create(attributes, &block)
end
- # Like <tt>find_or_create_by</tt>, but calls <tt>create!</tt> so an exception is raised if the created record is invalid.
+ # Like <tt>find_or_create_by</tt>, but calls <tt>create!</tt> so an exception
+ # is raised if the created record is invalid.
def find_or_create_by!(attributes, &block)
find_by(attributes) || create!(attributes, &block)
end
@@ -210,7 +247,7 @@ module ActiveRecord
def empty?
return @records.empty? if loaded?
- c = count
+ c = count(:all)
c.respond_to?(:zero?) ? c.zero? : c.empty?
end
@@ -475,11 +512,13 @@ module ActiveRecord
# User.where(name: 'Oscar').where_values_hash
# # => {name: "Oscar"}
def where_values_hash
- equalities = with_default_scope.where_values.grep(Arel::Nodes::Equality).find_all { |node|
+ scope = with_default_scope
+ equalities = scope.where_values.grep(Arel::Nodes::Equality).find_all { |node|
node.left.relation.name == table_name
}
- binds = Hash[bind_values.find_all(&:first).map { |column, v| [column.name, v] }]
+ binds = Hash[scope.bind_values.find_all(&:first).map { |column, v| [column.name, v] }]
+ binds.merge!(Hash[bind_values.find_all(&:first).map { |column, v| [column.name, v] }])
Hash[equalities.map { |where|
name = where.left.name
@@ -566,10 +605,7 @@ module ActiveRecord
ActiveRecord::Associations::Preloader.new(@records, associations).run
end
- # @readonly_value is true only if set explicitly. @implicit_readonly is true if there
- # are JOINS and no explicit SELECT.
- readonly = readonly_value.nil? ? @implicit_readonly : readonly_value
- @records.each { |record| record.readonly! } if readonly
+ @records.each { |record| record.readonly! } if readonly_value
else
@records = default_scoped.to_a
end