删除空值并修复对齐

Question

我正在使用 SQL Server，并使用 SMSS 进行查询。我不是一个全职的 SQL 用户，我正在尝试为我们的工作人员制作一些仪表板，使用 SQL 作为数据收集器，并使用下面的查询。

查询几乎可以正常工作，但我需要将所有结果放入成对的行中，而不是显示空值。这是我写的查询：

SELECT convert(varchar(11), start_time, 103) AS Date, DATENAME(weekday, start_time) AS Week_Day,
CASE WHEN CAST(start_time AS time) = '05:00:00'
THEN name
END AS 'Morning',
CASE WHEN CAST(start_time AS time) ='12:59:59'
THEN name
END AS 'Afternoon',
CASE WHEN CAST(start_time AS time) = '20:59:59'
THEN name
END AS 'Evening'
FROM [somedb].[dbo].[tb_some_table]
WHERE [start_time] >= dateadd(day, 2-datepart(dw, getdate()), CONVERT(date,getdate()))
AND [start_time] < dateadd(day, 9-datepart(dw, getdate()), CONVERT(date,getdate()))

这给了我这样的结果：

Date       Week_Day Morning Afternoon Evening
24/08/2020 Monday   Fred    NULL      NULL
24/08/2020 Monday   Markus  NULL      NULL
24/08/2020 Monday   NULL    Chuck     NULL
24/08/2020 Monday   NULL    Bill      NULL
24/08/2020 Monday   NULL    NULL      John
24/08/2020 Monday   NULL    NULL      Wayne

但是，我想得到这个：

Date       Week_Day Morning Afternoon Evening
24/08/2020 Monday   Fred    Chuck     John
24/08/2020 Monday   Markus  Bill      Wayne

谁能帮帮我？ ：/

编辑：数据如下所示：

如果我运行一个选择，数据看起来像这样：

start_time              end_time                name

2020-08-24 05:00:00.000 2020-08-24 12:59:59.000 Frank
2020-08-24 05:00:00.000 2020-08-24 12:59:59.000 Markus
2020-08-24 12:59:59.000 2020-08-24 20:59:59.000 Chuck
2020-08-24 12:59:59.000 2020-08-24 20:59:59.000 Bill
2020-08-24 20:59:59.000 2020-08-25 05:00:00.000 John
2020-08-24 20:59:59.000 2020-08-25 05:00:00.000 Wayne

Answer 1

我想你想要聚合：

SELECT CONVERT(DATE, start_time) as date,
       DATENAME(weekday, MIN(start_time)) AS Week_Day,
       MAX(CASE WHEN CAST(start_time AS time) = '05:00:00' THEN name END) AS Morning,
       MAX(CASE WHEN CAST(start_time AS time) = '12:59:59' THEN name END) AS Afternoon,
       MAX(CASE WHEN CAST(start_time AS time) = '20:59:59' THEN name END) AS Evening
FROM (SELECT t.*,
             ROW_NUMBER() OVER (PARTITION BY start_time ORDER BY start_time) as seqnum
      FROM [somedb].[dbo].[tb_some_table] t
      WHERE start_time >= dateadd(day, 2-datepart(dw, getdate()), CONVERT(date, getdate())) AND
            start_time < dateadd(day, 9-datepart(dw, getdate()), CONVERT(date, getdate()))
     ) t
GROUP BY CONVERT(DATE, start_time), seqnum;

请注意，您需要每个日期多行。 ROW_NUMBER() 正在确定这一点。

注意事项：

• 您无需将日期转换为字符串即可提取日期组件。仅当您确实需要特定格式的日期时才使用 convert()。
• 时间是准确的似乎很奇怪。我希望范围。如果真的是这样，那就问一个新问题。它会改变查询。
• 仅对字符串和日期常量使用单引号。不要将它们用于列名 - 当（有一天）您认为您使用单引号引用列时，这只会导致难以调试的错误。