在punching_bag
github頁面中,它說我可以運行rake punching_bag:combine
來組合點擊。運行耙子時沙袋出錯
當我運行這個rake
我得到以下錯誤:
SELECT DISTINCT "punches"."punchable_type" FROM "punches" ORDER BY punches.average_time DESC
01 PG::InvalidColumnReference: ERROR: for SELECT DISTINCT, ORDER BY expressions must appear in select list
01 LINE 1: ...unches"."punchable_type" FROM "punches" ORDER BY punches.av...
01 ^
01 : SELECT DISTINCT "punches"."punchable_type" FROM "punches" ORDER BY punches.average_time DESC
01 rake aborted!
01 ActiveRecord::StatementInvalid: PG::InvalidColumnReference: ERROR: for SELECT DISTINCT, ORDER BY expressions must appear in select list
01 LINE 1: ...unches"."punchable_type" FROM "punches" ORDER BY punches.av...
01
什麼是錯的,我怎麼能解決這個問題?