2020-10-13から1日間の記事一覧
Streakを計算したいときに思い出すSQL。 SELECT MAX(streak) AS streak FROM ( SELECT tmp1.*, IF( @prev + INTERVAL 1 DAY = tmp1.date, @streak := @streak + 1, @streak := 1 ) AS streak, @prev := tmp1.date FROM ( SELECT date FROM logs WHERE user_i…
Streakを計算したいときに思い出すSQL。 SELECT MAX(streak) AS streak FROM ( SELECT tmp1.*, IF( @prev + INTERVAL 1 DAY = tmp1.date, @streak := @streak + 1, @streak := 1 ) AS streak, @prev := tmp1.date FROM ( SELECT date FROM logs WHERE user_i…