Question

我在main table中有一些数据：

| id | Attendance              | Accountability          | Respect                    |   |
|----|-------------------------|-------------------------|----------------------------|---|
| 1  | John was always on time | John is accountable     | John is always respectful  |   |
| 2  | Ann never missed a day  | Ann is very accountable |                            |   |
| 3  |                         |                         | Dan was very disrespectful |   |

我需要计算每行的非空单元格数，然后排序到范围。

示例：

首先计算非空单元格。

| id | Non-empty |
|----|-----------|
| 1  | 3         | # Row 1 has 3 comments
| 2  | 2         | # Row 2 has 2 comments and 1 empty cell
| 3  | 1         | # Row 3 has 1 comment and 2 empty cells

我们将此结果称为“表A”

然后根据留下的评论范围创建分组。 这是最终结果。

| id | Range        | Count |
|----|--------------|-------|
| 1  | 1-2 comments | 2     | # 2 rows have between 1 and 2 comments
| 2  | 3-4 comments | 1     | # 1 row has between 3 and 4 comments
| 3  | 5+ comments  | 0     | # 0 rows have more than 5 comments

我们将此结果称为“表B”

我做了什么

select 
  case 
    when Non-empty between 1 and 2 then '1-2 comments'
    when Non-empty between 3 and 4 then '3-4 comments'
    else then '5+ comments'
  end as `Range`,
 count(1) as `Count`
from `Table A`
group by `Range`

此查询应生成表A中的表B

我需要什么

从主表生成表B的单个SQL查询。

所以，我想我需要一个可以生成表A的查询，然后将它与上面的查询结合起来。

如果有更简单的方法从主表中获取表B，那么我欢迎它！

Answer 1

在这个例子中，我使用了：

Case Expression - 识别非空单元格
Between和Sum运营商 - 获取范围和行数

Unpivot - 将表值表达式更改为另一个表

    --- Source
    CREATE TABLE Main
        (
          id INT ,
          attendance VARCHAR(254) ,
          Accountability VARCHAR(254) ,
          Respect VARCHAR(254)
        )

    INSERT  INTO Main
            ( id, attendance, accountability, respect )
    VALUES  ( 1, 'John was always on time', 'John is accountable',
              'John is always respectful' ),
            ( 2, 'Ann never missed a day', 'Ann is very accountable', NULL ),
            ( 3, NULL, NULL, 'Dan was very disrespectful' )


    --- Query
    SELECT  ROW_NUMBER() OVER(ORDER BY col) id,
            col [range],
            val [count]
    FROM    ( SELECT    SUM(CASE WHEN ctr BETWEEN 1 AND 2 THEN 1
                                 ELSE 0
                            END) [1-2 comments] ,
                        SUM(CASE WHEN ctr BETWEEN 3 AND 4 THEN 1
                                 ELSE 0
                            END) [3-4 comments] ,
                        SUM(CASE WHEN ctr >= 5 THEN 1
                                 ELSE 0
                            END) [5+ comments]
              FROM      ( SELECT    attendance + Accountability + Respect [ctr]
                          FROM      ( SELECT    CASE WHEN attendance IS NOT NULL
                                                          OR attendance <> ''
                                                     THEN 1
                                                     ELSE 0
                                                END attendance ,
                                                CASE WHEN Accountability IS NOT NULL
                                                          OR Accountability <> ''
                                                     THEN 1
                                                     ELSE 0
                                                END Accountability ,
                                                CASE WHEN Respect IS NOT NULL
                                                          OR Respect <> '' THEN 1
                                                     ELSE 0
                                                END Respect
                                      FROM      Main
                                    ) T
                        ) Tmain
            ) TBL UNPIVOT( val FOR col IN ( [1-2 comments], [3-4 comments],
                                            [5+ comments] ) ) UPVT



    DROP TABLE Main

结果

    id                   range               count
    -------------------- ------------------- -----------
    1                    1-2 comments        2
    2                    3-4 comments        1
    3                    5+ comments         0

    (3 row(s) affected)

Answer 2

这是对我有用的最终查询。

谢谢你@flip！你的回答让我最接近。

SELECT
    case 
        when comments between 1 and 2 then '1-2 comments'
        when comments between 3 and 4 then '3-4 comments'
        else '5+ comments'
    end as `Range`,
    count(1) as `Count` 
FROM( 
    SELECT id, 
        SUM(IF(Respect != '', 1, 0)) +
        SUM(IF(Accountability != '', 1, 0)) + 
        SUM(IF(Attendance != '', 1, 0))
    FROM `main table` 
    GROUP BY id
)AS T GROUP BY `Range`;

SQL计数行中的非空单元格和按范围分组

3 个答案: