1 files changed, 153 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/insert_all.rb b/activerecord/lib/active_record/insert_all.rb
new file mode 100644
index 0000000000..ca5ce11d79
--- /dev/null
+++ b/activerecord/lib/active_record/insert_all.rb
@@ -0,0 +1,153 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  class InsertAll
+    attr_reader :model, :connection, :inserts, :on_duplicate, :returning, :unique_by
+
+    def initialize(model, inserts, on_duplicate:, returning: nil, unique_by: nil)
+      @model, @connection, @inserts, @on_duplicate, @returning, @unique_by = model, model.connection, inserts, on_duplicate, returning, unique_by
+      @returning = (connection.supports_insert_returning? ? primary_keys : false) if @returning.nil?
+      @returning = false if @returning == []
+      @on_duplicate = :skip if @on_duplicate == :update && updatable_columns.empty?
+
+      ensure_valid_options_for_connection!
+    end
+
+    def execute
+      if inserts.present?
+        connection.exec_query to_sql, "Bulk Insert"
+      else
+        ActiveRecord::Result.new([], [])
+      end
+    end
+
+    def keys
+      inserts.present? ? inserts.first.keys.map(&:to_s) : []
+    end
+
+    def updatable_columns
+      keys - readonly_columns - unique_by_columns
+    end
+
+    def skip_duplicates?
+      on_duplicate == :skip
+    end
+
+    def update_duplicates?
+      on_duplicate == :update
+    end
+
+    private
+      def ensure_valid_options_for_connection!
+        if returning && !connection.supports_insert_returning?
+          raise ArgumentError, "#{connection.class} does not support :returning"
+        end
+
+        unless %i{ raise skip update }.member?(on_duplicate)
+          raise NotImplementedError, "#{on_duplicate.inspect} is an unknown value for :on_duplicate. Valid values are :raise, :skip, and :update"
+        end
+
+        if on_duplicate == :skip && !connection.supports_insert_on_duplicate_skip?
+          raise ArgumentError, "#{connection.class} does not support skipping duplicates"
+        end
+
+        if on_duplicate == :update && !connection.supports_insert_on_duplicate_update?
+          raise ArgumentError, "#{connection.class} does not support upsert"
+        end
+
+        if unique_by && !connection.supports_insert_conflict_target?
+          raise ArgumentError, "#{connection.class} does not support :unique_by"
+        end
+      end
+
+      def to_sql
+        connection.build_insert_sql(ActiveRecord::InsertAll::Builder.new(self))
+      end
+
+      def readonly_columns
+        primary_keys + model.readonly_attributes.to_a
+      end
+
+      def unique_by_columns
+        unique_by ? unique_by.fetch(:columns).map(&:to_s) : []
+      end
+
+      def primary_keys
+        Array.wrap(model.primary_key)
+      end
+
+
+      class Builder
+        attr_reader :model
+
+        delegate :skip_duplicates?, :update_duplicates?, to: :insert_all
+
+        def initialize(insert_all)
+          @insert_all, @model, @connection = insert_all, insert_all.model, insert_all.connection
+        end
+
+        def into
+          "INTO #{model.quoted_table_name}(#{columns_list})"
+        end
+
+        def values_list
+          columns = connection.schema_cache.columns_hash(model.table_name)
+          keys = insert_all.keys.to_set
+          types = keys.map { |key| [ key, connection.lookup_cast_type_from_column(columns[key]) ] }.to_h
+
+          values_list = insert_all.inserts.map do |attributes|
+            attributes = attributes.stringify_keys
+
+            unless attributes.keys.to_set == keys
+              raise ArgumentError, "All objects being inserted must have the same keys"
+            end
+
+            keys.map do |key|
+              bind = Relation::QueryAttribute.new(key, attributes[key], types[key])
+              connection.with_yaml_fallback(bind.value_for_database)
+            end
+          end
+
+          Arel::InsertManager.new.create_values_list(values_list).to_sql
+        end
+
+        def returning
+          quote_columns(insert_all.returning).join(",") if insert_all.returning
+        end
+
+        def conflict_target
+          return unless conflict_columns
+          sql = +"(#{quote_columns(conflict_columns).join(',')})"
+          sql << " WHERE #{where}" if where
+          sql
+        end
+
+        def updatable_columns
+          quote_columns(insert_all.updatable_columns)
+        end
+
+        private
+          attr_reader :connection, :insert_all
+
+          def columns_list
+            quote_columns(insert_all.keys).join(",")
+          end
+
+          def quote_columns(columns)
+            columns.map(&connection.method(:quote_column_name))
+          end
+
+          def conflict_columns
+            @conflict_columns ||= begin
+              conflict_columns = insert_all.unique_by.fetch(:columns) if insert_all.unique_by
+              conflict_columns ||= Array.wrap(model.primary_key) if update_duplicates?
+              conflict_columns
+            end
+          end
+
+          def where
+            insert_all.unique_by && insert_all.unique_by[:where]
+          end
+      end
+  end
+end