method

columns_for_distinct

Ruby on Rails latest stable (v6.1.7.7) - 0 notes - Class: ActiveRecord::ConnectionAdapters

1.0.0
1.1.6
1.2.6
2.0.3
2.1.0
2.2.1
2.3.8
3.0.0
3.0.9
3.1.0
3.2.1
3.2.8
3.2.13
4.0.2
4.1.8
4.2.1
4.2.7
4.2.9
5.0.0.1 (0)
5.1.7 (0)
5.2.3 (0)
6.0.0
6.1.3.1
6.1.7.7
7.0.0
7.1.3.2
What's this?

Method deprecated or moved

This method is deprecated or moved on the latest stable version. The last existing version (v5.2.3) is shown here.

These similar methods exist in v6.1.7.7:

columns_for_distinct(columns, orders) public

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 dev.mysql.com/doc/refman/5.7/en/group-by-handling.html

Show source

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 510
      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/, "")
        }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" }

        (order_columns << super).join(", ")
      end

columns_for_distinct

Related methods

Method deprecated or moved

Flowdock - Team Inbox With Chat