diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb')
-rw-r--r-- | activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb | 15 |
1 files changed, 15 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 b9a9c22198..068bf356e8 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb @@ -786,6 +786,21 @@ module ActiveRecord end end + # In MySQL 5.7.5 and up, ONLY_FULL_GROUP_BY affects handling of queries that use + # DISTINCT and ORDER BY. It requires the ORDER BY columns in the select list for + # distinct queries, and requires that the ORDER BY include the distinct column. + # See https://dev.mysql.com/doc/refman/5.7/en/group-by-handling.html + def columns_for_distinct(columns, orders) # :nodoc: + order_columns = orders.reject(&:blank?).map { |s| + # Convert Arel node to string + s = s.to_sql unless s.is_a?(String) + # Remove any ASC/DESC modifiers + s.gsub(/\s+(?:ASC|DESC)\b/i, '') + }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" } + + [super, *order_columns].join(', ') + end + def strict_mode? self.class.type_cast_config_to_boolean(@config.fetch(:strict, true)) end |