当数据中不存在空值时,SQL Server动态透视返回空值

我有三张桌子( tblPreference , tblCustomer , tblCustomerPreference )看起来像是:

tblPreference:
ID       | Name            | DefaultValue
(int PK) | (nvarchar(100)) | (nvarchar(100))
-------------------------------
1        | Preference1     | 1
2        | Preference2     | Yes
3        | Preference3     | 1

tblCustomer:
CustomerID | ...
(int PK)
--------------------
1          | ...
2          | ...
3          | ...

tblCustomerPreference:
ID       | CustomerID | PreferenceID | Value
(int PK) | (int)      | (int)        | (nvarchar(100))
-------------------------------------------------------
1        | 1          | 1            | 0
2        | 1          | 2            | Yes
3        | 2          | 1            | 0
4        | 2          | 2            | No

我正在创建此数据的透视图,因此所有数据都在一行中,使用以下存储过程,这样它将始终回退所有首选项,如果找到特定于客户的值,它将返回该值,否则它将返回默认值:

CREATE PROCEDURE [dbo].[usp_GetCustomerPreferences] @CustomerID int AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from interfering with SELECT statements.
    SET NOCOUNT ON;

    DECLARE @PivotColumns nvarchar(max)
    DECLARE @PivotColumnsSelectable nvarchar(max)
    SELECT @PivotColumns = COALESCE(@PivotColumns + ',','') + QUOTENAME(Preference.Name),
           @PivotColumnsSelectable = COALESCE(@PivotColumnsSelectable + ',' + Char(10),'') + Preference.Source + '.' + QUOTENAME(Preference.Name) + ' AS ' + QUOTENAME(Preference.Name)
    FROM (SELECT [Name],
                 'PreferencePivot' AS [Source]
          FROM [dbo].[tblPreference]) Preference

    DECLARE @sqlText nvarchar(max)
    SELECT @sqlText = 'SELECT ' + @PivotColumnsSelectable + '
    FROM (SELECT tblPreference.Name AS PreferenceName,
                CASE
                    WHEN tblCustomerPreference.Value IS NOT NULL THEN tblCustomerPreference.Value
                    ELSE tblPreference.DefaultValue
                END AS Value,
                @innerCustomerID AS CustomerID
            FROM tblCustomerPreference
                RIGHT JOIN tblPreference ON tblCustomerPreference.PreferenceID = tblPreference.ID
            WHERE (tblCustomerPreference.CustomerID = @innerCustomerID OR tblCustomerPreference.ID IS NULL)) data
            PIVOT (MAX(Value)
                   FOR PreferenceName IN (' + @PivotColumns + ')) PreferencePivot'

    EXECUTE sp_executesql @sqlText, N'@innerCustomerID int', @CustomerID
END

我遇到的问题是,当我查询customerid 1或2时,所有内容都按预期返回,并按预期填充所有值。但如果我查询customerid 3,它将返回 NULL 对于为其他客户填充的任何首选项ID。如果运行查询时没有 PIVOT 表达式它返回按预期填充的所有首选项。只有当我透视数据时 无效的 爬进去。我希望我错过了一些简单的事情,但我没有看到错误。