instance method foreign_keys

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 368
      def foreign_keys(table_name)
        # SQLite returns 1 row for each column of composite foreign keys.
        fk_info = internal_exec_query("PRAGMA foreign_key_list(#{quote(table_name)})", "SCHEMA")
        grouped_fk = fk_info.group_by { |row| row["id"] }.values.each { |group| group.sort_by! { |row| row["seq"] } }
        grouped_fk.map do |group|
          row = group.first
          options = {
            on_delete: extract_foreign_key_action(row["on_delete"]),
            on_update: extract_foreign_key_action(row["on_update"])
          }

          if group.one?
            options[:column] = row["from"]
            options[:primary_key] = row["to"]
          else
            options[:column] = group.map { |row| row["from"] }
            options[:primary_key] = group.map { |row| row["to"] }
          end
          ForeignKeyDefinition.new(table_name, row["table"], options)
        end
      end