替换动态数据透视 sql 查询中的空值

问题描述

图像转录:

FTE/RATE CARD | 2018-01-01 | 2018-02-01 | 2018-03-01 | 2018-04-01 | 2018-05-01 | 2018-06-01 | ...
-------------------------------------------------------------------------------------------------
FTE 3         | NULL       | NULL       | NULL       | 33         | 38         | 40.5       | ...

我有一个数据透视 sql 查询，如下所示.我需要在结果中用零替换 NULL 值.我不知道在查询中我究竟在哪里使用 IsNull 或 Coalesce 函数.

I have a pivot sql query as below. I need to replace NULL values with Zeros in the result. I don't know where do I exactly use the IsNull or Coalesce function in the query.

DECLARE @cols AS NVARCHAR(MAX),
        @query AS NVARCHAR(MAX) 
SELECT  @cols = STUFF
(
(
SELECT distinct ',' + QUOTENAME([MONTH])
FROM   [HEADCOUNT]
WHERE  [MONTH] BETWEEN '01-012018' AND '12-01-2018'
ORDER BY ',' + QUOTENAME([MONTH])
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'),1,1,''
)
SET     @query = 'SELECT [FTE/RATE CARD],' + @cols + ' FROM
(
SELECT  [MONTH],[FTE/RATE CARD],[HC]
FROM    [HEADCOUNT]
WHERE   [CC-LOC] IN ([CC-LOC]) 

) x pivot (Sum ([HC]) for [MONTH] in (' + @cols + '))p' execute(@query)

推荐答案

您需要为 select 语句生成另一个列列表，并用 ISNULL 包裹各个月份，如下所示:

You'll need to generate another column list for the select statement, and wrap individual months with ISNULL, like so:

DECLARE @cols AS NVARCHAR(MAX),
        @selectCols AS NVARCHAR(MAX),
        @query AS NVARCHAR(MAX) 

SELECT  @selectCols = STUFF
(
(
SELECT distinct ', ISNULL(' + QUOTENAME([MONTH]) + ', 0) AS ' + QUOTENAME([MONTH])
FROM   [HEADCOUNT]
WHERE  [MONTH] BETWEEN '01-012018' AND '12-01-2018'
ORDER BY ',' + QUOTENAME([MONTH])
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'),1,1,''
)



SELECT  @cols = STUFF
(
(
SELECT distinct ',' + QUOTENAME([MONTH])
FROM   [HEADCOUNT]
WHERE  [MONTH] BETWEEN '01-012018' AND '12-01-2018'
ORDER BY ',' + QUOTENAME([MONTH])
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'),1,1,''
)
SET     @query = 'SELECT [FTE/RATE CARD],' + @selectCols + ' FROM
(
SELECT  [MONTH],[FTE/RATE CARD],[HC]
FROM    [HEADCOUNT]
WHERE   [CC-LOC] IN ([CC-LOC]) 

) x pivot (Sum ([HC]) for [MONTH] in (' + @cols + '))p' execute(@query)