如果与上一行相同，如何将后续行值设置为空

Question

如何转换这个 table:

+---------------------+-------------------------------+-------+-------+
|       PropertyName  |           Emergency           | Count | Total |
+---------------------+-------------------------------+-------+-------+
| IH                  | No                            |     8 |    12 |
| IH                  | No Water                      |     1 |    12 |
| IH                  | Smoke  Alarm not working      |     1 |    12 |
| IH                  | Broken Lock - Exterior        |     1 |    12 |
| IH                  | Leaking Water                 |     1 |    12 |
| GG                  | No                            |     5 |    10 |
| GG                  | Leaking Water                 |     3 |    10 |
| GG                  | Property Damage (Significant) |     1 |    10 |
| GG                  | Toilet - Clogged (1 Bathroom) |     1 |    10 |
| PLB                 | No                            |     5 |    10 |
| PLB                 | Resident Locked Out           |     2 |    10 |
| PLB                 | Smoke  Alarm not working      |     1 |    10 |
| PLB                 | Tub - Clogged (1 Bathroom)    |     1 |    10 |
| PLB                 | Leaking Water                 |     1 |    10 |
+---------------------+-------------------------------+-------+-------+

像这样：

+---------------------+-------------------------------+-------+-------+
|       PropertyName  |           Emergency           | Count | Total |
+---------------------+-------------------------------+-------+-------+
| IH                  | No                            |     8 |    12 |
|                     | No Water                      |     1 |       |
|                     | Smoke  Alarm not working      |     1 |       |
|                     | Broken Lock - Exterior        |     1 |       |
|                     | Leaking Water                 |     1 |       |
| GG                  | No                            |     5 |    10 |
|                     | Leaking Water                 |     3 |       |
|                     | Property Damage (Significant) |     1 |       |
|                     | Toilet - Clogged (1 Bathroom) |     1 |       |
| PLB                 | No                            |     5 |    10 |
|                     | Resident Locked Out           |     2 |       |
|                     | Smoke  Alarm not working      |     1 |       |
|                     | Tub - Clogged (1 Bathroom)    |     1 |       |
|                     | Leaking Water                 |     1 |       |
+---------------------+-------------------------------+-------+-------+

我想做的是，如果 PropertyName 与上一行相同，则应省略后续行。这应该与总计相同。

我不能尝试 LAG/LEAD 因为我们只使用 SQL SERVER 2008 - 我知道这很糟糕。

Answer 1

一般来说，这最好在应用程序级别完成。但是，在您的情况下，您似乎只想要 "No" 行上的值。您可以使用一些 case 表达式来做到这一点：

select (case when Emergency = 'No' then PropertyName end) as PropertyName,
       Emergency, Count,
       (case when Emergency = 'No' then Total end) as total
from t
order by max(total) over (partition by PropertyName) desc,  -- you seem to want the largest total first
         t.PropertyName, 
         (case when Emergency = 'No' then 1 else 2 end),
         t.Total desc;

ORDER BY非常重要。 SQL 查询不能保证以任何特定顺序 return 结果 除非最外面的 SELECT 有一个 ORDER BY.

Answer 2

您可以在 CTE 表达式中生成行号，然后 select 每个 PropertyName:

最上面的行号

  ;with tableWithRowNums as( 
    select ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS rownum, 
            PropertyName,
            Emergency,
            Count,
            Total
    from the_table ),
  first_rows as (
    select min(rownum) as first_row,
            PropertyName 
    from tableWithRowNums
    group by rowNums.PropertyName
  )
  select ISNULL(first_rows.PropertyName, ''),
        tableWithRowNums.Emergency,
        tableWithRowNums.Count,
        tableWithRowNums.Total  
  from tableWithRowNums
    left join first_rows on first_rows.first_row = tableWithRowNums.rownum
  order by tableWithRowNums.rownum;

如果与上一行相同，如何将后续行值设置为空

How to set succeeding row values as empty if same with previous row

sql

sql-server

sql-server-2008