Add insert_all to ActiveRecord models (#35077)

Adds a method to ActiveRecord allowing records to be inserted in bulk without instantiating ActiveRecord models. This method supports options for handling uniqueness violations by skipping duplicate records or overwriting them in an UPSERT operation.

ActiveRecord already supports bulk-update and bulk-destroy actions that execute SQL UPDATE and DELETE commands directly. It also supports bulk-read actions through `pluck`. It makes sense for it also to support bulk-creation.

1 files changed, 22 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 96f902792e..1aab36c865 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -109,6 +109,14 @@ module ActiveRecord
         true
       end
 
+      def supports_insert_on_duplicate_skip?
+        true
+      end
+
+      def supports_insert_on_duplicate_update?
+        true
+      end
+
       def get_advisory_lock(lock_name, timeout = 0) # :nodoc:
         query_value("SELECT GET_LOCK(#{quote(lock_name.to_s)}, #{timeout})") == 1
       end
@@ -511,6 +519,20 @@ module ActiveRecord
         end
       end
 
+      def build_insert_sql(insert) # :nodoc:
+        sql = +"INSERT #{insert.into} #{insert.values_list}"
+
+        if insert.skip_duplicates?
+          any_column = quote_column_name(insert.model.columns.first.name)
+          sql << " ON DUPLICATE KEY UPDATE #{any_column}=#{any_column}"
+        elsif insert.update_duplicates?
+          sql << " ON DUPLICATE KEY UPDATE "
+          sql << insert.updatable_columns.map { |column| "#{column}=VALUES(#{column})" }.join(",")
+        end
+
+        sql
+      end
+
       private
         def check_version
           if version < "5.5.8"