Sql server SQL Server：如何用剩余的零值填充稀疏数据？

我有每个月和每个客户的销售数据报告。当我计算这些值时，由于sparsa数据格式的原因，不会报告零值

假设客户1-4。假设只有客户1-2有录音。直线表在行上有customerid，在列上有month，因此

|CustomerID|MonthID|Value|
-------------------------|
|     1    |201101 |  10 |
|     2    |201101 | 100 |

|CustomerID|201101|201102|2011103|...|201501|
---------------------------------------------
|    1     |  10  |   0  |   0   |...|  0   |  
|    2     |  100 |   0  |   0   |...|  0   |
|    3     |  0   |   0  |   0   |...|  0   |
|    4     |  0   |   0  |   0   |...|  0   |

然后它们以交叉表格式报告，这样

|CustomerID|MonthID|Value|
-------------------------|
|     1    |201101 |  10 |
|     2    |201101 | 100 |

|CustomerID|201101|201102|2011103|...|201501|
---------------------------------------------
|    1     |  10  |   0  |   0   |...|  0   |  
|    2     |  100 |   0  |   0   |...|  0   |
|    3     |  0   |   0  |   0   |...|  0   |
|    4     |  0   |   0  |   0   |...|  0   |

当我计算这些时，客户3-4没有得到任何东西，因为他们没有录音。我想得到丢失的零行。如何填充或选择原始数据并将不存在的零值填充到选择中？或者更简短地说：

---

处理稀疏数据格式并在最终报告中保持零客户的最优雅方式是什么？

在转向交叉表格式之前，您将

交叉连接
表
客户
和
月
，然后
左连接
表
销售

select 
    c.CustomerId
  , m.MonthId
  , Value = isnull(s.Value,0)
from customers c
  cross join months m
  left join sales s
    on s.CustomerId = c.CustomerId
   and s.MonthId = m.MonthId

rextester演示：

返回：

+------------+---------+-------+
| CustomerId | MonthId | Value |
+------------+---------+-------+
|          1 |  201101 |    10 |
|          2 |  201101 |   100 |
|          3 |  201101 |     0 |
|          4 |  201101 |     0 |
|          1 |  201102 |     0 |
|          2 |  201102 |     0 |
|          3 |  201102 |     0 |
|          4 |  201102 |     0 |
|          1 |  201103 |     0 |
|          2 |  201103 |     0 |
|          3 |  201103 |     0 |
|          4 |  201103 |     0 |
+------------+---------+-------+

+-----------------------------------------------------------------------+
|                             CodeGenerated                             |
+-----------------------------------------------------------------------+
| select CustomerId, [201101],[201102],[201103]                         |
| from (                                                                |
|     select                                                            |
|         c.CustomerId                                                  |
|       , m.MonthId                                                     |
|       , Value = isnull(s.Value,0)                                     |
|     from customers c                                                  |
|       cross join months m                                             |
|       left join sales s                                               |
|         on s.CustomerId = c.CustomerId                                |
|       and s.MonthId = m.MonthId                                       |
|     ) as t                                                            |
| pivot (sum([Value]) for [MonthId] in ([201101],[201102],[201103]) ) p |
+-----------------------------------------------------------------------+


向上面添加动态
pivot（）
，方法如下：

declare @cols nvarchar(max);
declare @sql  nvarchar(max);

select @cols = stuff((
    select ',' + quotename(MonthId)
    from months 
    order by MonthId
    for xml path (''), type).value('.','nvarchar(max)')
  ,1,1,'');

select @sql = '
select CustomerId, ' + @cols + '
from (
    select 
        c.CustomerId
      , m.MonthId
      , Value = isnull(s.Value,0)
    from customers c
      cross join months m
      left join sales s
        on s.CustomerId = c.CustomerId
      and s.MonthId = m.MonthId
    ) as t
pivot (sum([Value]) for [MonthId] in (' + @cols + ') ) p';

select @sql as CodeGenerated;
exec sp_executesql @sql;

返回：

+------------+---------+-------+
| CustomerId | MonthId | Value |
+------------+---------+-------+
|          1 |  201101 |    10 |
|          2 |  201101 |   100 |
|          3 |  201101 |     0 |
|          4 |  201101 |     0 |
|          1 |  201102 |     0 |
|          2 |  201102 |     0 |
|          3 |  201102 |     0 |
|          4 |  201102 |     0 |
|          1 |  201103 |     0 |
|          2 |  201103 |     0 |
|          3 |  201103 |     0 |
|          4 |  201103 |     0 |
+------------+---------+-------+

+-----------------------------------------------------------------------+
|                             CodeGenerated                             |
+-----------------------------------------------------------------------+
| select CustomerId, [201101],[201102],[201103]                         |
| from (                                                                |
|     select                                                            |
|         c.CustomerId                                                  |
|       , m.MonthId                                                     |
|       , Value = isnull(s.Value,0)                                     |
|     from customers c                                                  |
|       cross join months m                                             |
|       left join sales s                                               |
|         on s.CustomerId = c.CustomerId                                |
|       and s.MonthId = m.MonthId                                       |
|     ) as t                                                            |
| pivot (sum([Value]) for [MonthId] in ([201101],[201102],[201103]) ) p |
+-----------------------------------------------------------------------+

而
exec
返回：

+------------+--------+--------+--------+
| CustomerId | 201101 | 201102 | 201103 |
+------------+--------+--------+--------+
|          1 |     10 |      0 |      0 |
|          2 |    100 |      0 |      0 |
|          3 |      0 |      0 |      0 |
|          4 |      0 |      0 |      0 |
+------------+--------+--------+--------+