回答編集履歴
3
体裁
    
        answer	
    CHANGED
    
    | @@ -39,7 +39,7 @@ | |
| 39 39 | 
             
            select 
         | 
| 40 40 | 
             
              user_id
         | 
| 41 41 | 
             
            , date
         | 
| 42 | 
            -
            , case when first_value(id) over(partition by user_id order by date | 
| 42 | 
            +
            , case when first_value(id) over(partition by user_id order by date) = id
         | 
| 43 43 | 
             
                   then 1 else 0 end as 初登場
         | 
| 44 44 | 
             
            from tx
         | 
| 45 45 | 
             
            ), sub2 as 
         | 
2
スキーマ定義を他の人の回答にあわせる
    
        answer	
    CHANGED
    
    | @@ -6,16 +6,16 @@ | |
| 6 6 | 
             
            select 
         | 
| 7 7 | 
             
              id
         | 
| 8 8 | 
             
            , user_id
         | 
| 9 | 
            -
            ,  | 
| 9 | 
            +
            , date
         | 
| 10 | 
            -
            , case when first_value(id) over(partition by user_id order by  | 
| 10 | 
            +
            , case when first_value(id) over(partition by user_id order by date, id) = id
         | 
| 11 11 | 
             
                   then 1 else 0 end as 初登場
         | 
| 12 | 
            -
            from  | 
| 12 | 
            +
            from tx
         | 
| 13 13 | 
             
            order by id
         | 
| 14 14 | 
             
            ```
         | 
| 15 15 |  | 
| 16 16 | 
             
            結果
         | 
| 17 17 |  | 
| 18 | 
            -
            | id   | user_id |  | 
| 18 | 
            +
            | id   | user_id | date      | 初登場 |
         | 
| 19 19 | 
             
            | :--- | :------ | :--------- | :----- |
         | 
| 20 20 | 
             
            | 1    | 1       | 1970-01-01 | 1      |
         | 
| 21 21 | 
             
            | 2    | 1       | 1970-01-01 | 0      |
         | 
| @@ -34,28 +34,28 @@ | |
| 34 34 | 
             
            上記の手法を使って、やりたいことを実現するSQLは以下となります。
         | 
| 35 35 |  | 
| 36 36 | 
             
            ```sql
         | 
| 37 | 
            -
            with sub1 | 
| 37 | 
            +
            with sub1 as 
         | 
| 38 38 | 
             
            (
         | 
| 39 39 | 
             
            select 
         | 
| 40 40 | 
             
              user_id
         | 
| 41 | 
            -
            ,  | 
| 41 | 
            +
            , date
         | 
| 42 | 
            -
            , case when first_value(id) over(partition by user_id order by  | 
| 42 | 
            +
            , case when first_value(id) over(partition by user_id order by date, id) = id
         | 
| 43 | 
            -
                   then 1 else 0 end
         | 
| 43 | 
            +
                   then 1 else 0 end as 初登場
         | 
| 44 | 
            -
            from  | 
| 44 | 
            +
            from tx
         | 
| 45 | 
            -
            ), sub2 | 
| 45 | 
            +
            ), sub2 as 
         | 
| 46 46 | 
             
            (
         | 
| 47 47 | 
             
            select
         | 
| 48 | 
            -
               | 
| 48 | 
            +
              date
         | 
| 49 49 | 
             
            , count(distinct user_id) as 日別UU
         | 
| 50 50 | 
             
            , sum(初登場) as 通算UU
         | 
| 51 51 | 
             
            from sub1
         | 
| 52 | 
            -
            group by  | 
| 52 | 
            +
            group by date
         | 
| 53 53 | 
             
            )
         | 
| 54 54 |  | 
| 55 55 | 
             
            select
         | 
| 56 | 
            -
               | 
| 56 | 
            +
              date
         | 
| 57 57 | 
             
            , 日別UU
         | 
| 58 | 
            -
            , sum(通算UU) over(order by  | 
| 58 | 
            +
            , sum(通算UU) over(order by date) as 通算UU
         | 
| 59 59 | 
             
            from sub2
         | 
| 60 | 
            -
            order by  | 
| 60 | 
            +
            order by date
         | 
| 61 61 | 
             
            ```
         | 
1
要約変更
    
        answer	
    CHANGED
    
    | @@ -1,4 +1,4 @@ | |
| 1 | 
            -
             | 
| 1 | 
            +
            結合や相関サブクエリを使わずにwindow関数のみで実現する方法を紹介します。
         | 
| 2 2 |  | 
| 3 3 | 
             
            通算UU でuser_idの重複を除いてカウントするために、user_idが初めて登場した行に初登場のフラグを立てます
         | 
| 4 4 |  | 
