Merge pull request #35854 from boblail/fix-bug-with-insert_all-on-mysql

When skipping duplicates in bulk insert on MySQL, avoid assigning an AUTONUMBER column when not specified

2 files changed, 4 insertions, 4 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 f5da19f0f6..ca8bbc14da 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -516,8 +516,8 @@ module ActiveRecord
         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}"
+          no_op_column = quote_column_name(insert.keys.first)
+          sql << " ON DUPLICATE KEY UPDATE #{no_op_column}=#{no_op_column}"
         elsif insert.update_duplicates?
           sql << " ON DUPLICATE KEY UPDATE "
           sql << insert.updatable_columns.map { |column| "#{column}=VALUES(#{column})" }.join(",")
diff --git a/activerecord/lib/active_record/insert_all.rb b/activerecord/lib/active_record/insert_all.rb
index 4b02d40aa0..d7808919ee 100644
--- a/activerecord/lib/active_record/insert_all.rb
+++ b/activerecord/lib/active_record/insert_all.rb
@@ -111,7 +111,7 @@ module ActiveRecord
       class Builder
         attr_reader :model
 
-        delegate :skip_duplicates?, :update_duplicates?, to: :insert_all
+        delegate :skip_duplicates?, :update_duplicates?, :keys, to: :insert_all
 
         def initialize(insert_all)
           @insert_all, @model, @connection = insert_all, insert_all.model, insert_all.connection
@@ -122,7 +122,7 @@ module ActiveRecord
         end
 
         def values_list
-          types = extract_types_from_columns_on(model.table_name, keys: insert_all.keys)
+          types = extract_types_from_columns_on(model.table_name, keys: keys)
 
           values_list = insert_all.map_key_with_value do |key, value|
             bind = Relation::QueryAttribute.new(key, value, types[key])