Sql 完全外部联接不会在右侧获取空值，而左侧确实存在空值

我必须比较两个来源EmployeeODS和EmployeeDWH，以获得新的或删除的记录，如下所示：

SELECT bf.EmployeeId AS EmployeeIdODS
      ,bf.FunctionId AS FunctionIdODS
      ,bf.Scope AS ScopeODS
      ,bf.Primacy AS PrimacyODS
      ,bn.EmployeeId AS EmployeeIdDWH
      ,bn.FunctionId AS FunctionIdDWH
      ,bn.Scope AS ScopeDWH
      ,bn.Primacy AS PrimacyDWH
      ,bn.BI_StartDate
      ,bn.BI_EndDate
       FROM EmployeeODS bf
FULL OUTER JOIN EmployeeDWH bn ON bf.EmployeeId = bn.EmployeeId 
AND bf.FunctionId=bn.FunctionId 
AND bf.Scope=bn.Scope
WHERE bf.EmployeeId=15366

输出如下所示：

EmployeeIdODS   FunctionIdODS   ScopeODS    PrimacyODS  EmployeeIdDWH   FunctionIdDWH   ScopeDWH    PrimacyDWH  BI_StartDate            BI_EndDate
15366           45              AMAGR       2           15366           45              AMAGR       2           2020-03-25              9999-12-31 
15366           940             AMATUN      1           15366           940             AMATUN      1           2020-03-25              9999-12-31 

当我从EmployeeODS中删除具有函数IDODS=45和ScopeODS='AMAGR'的记录时：

DELETE FROM EmployeeODS WHERE EmployeeId=15366 AND Scope='AMAGR' AND FunctionId=45

我得到以下输出：

EmployeeIdODS   FunctionIdODS   ScopeODS    PrimacyODS  EmployeeIdDWH   FunctionIdDWH   ScopeDWH    PrimacyDWH  BI_StartDate            BI_EndDate
15366           940             AMATUN      1           15366           940             AMATUN      1           2020-03-25              9999-12-31 

EmployeeIdODS   FunctionIdODS   ScopeODS    PrimacyODS  EmployeeIdDWH   FunctionIdDWH   ScopeDWH    PrimacyDWH  BI_StartDate            BI_EndDate
NULL            NULL            NULL        NULL        15366           45              AMAGR       2           2020-03-25              9999-12-31 
15366           940             AMATUN      1           15366           940             AMATUN      1           2020-03-25              9999-12-31 

我的预期产出：

EmployeeIdODS   FunctionIdODS   ScopeODS    PrimacyODS  EmployeeIdDWH   FunctionIdDWH   ScopeDWH    PrimacyDWH  BI_StartDate            BI_EndDate
15366           940             AMATUN      1           15366           940             AMATUN      1           2020-03-25              9999-12-31 

EmployeeIdODS   FunctionIdODS   ScopeODS    PrimacyODS  EmployeeIdDWH   FunctionIdDWH   ScopeDWH    PrimacyDWH  BI_StartDate            BI_EndDate
NULL            NULL            NULL        NULL        15366           45              AMAGR       2           2020-03-25              9999-12-31 
15366           940             AMATUN      1           15366           940             AMATUN      1           2020-03-25              9999-12-31 

WHERE子句将完全联接转换为较小类型的外部联接

对于完全联接，我建议在子查询中进行筛选：

   FROM (SELECT bf.*
         FROM EmployeeODS bf
         WHERE bf.EmployeeId = 15366
        ) FULL JOIN
        (SELECT bn.*
         FROM EmployeeDWH bn
         WHERE bn.EmployeeId = 15366
        ) bn
        ON bf.EmployeeId = bn.EmployeeId AND
           bf.FunctionId = bn.FunctionId AND
           bf.Scope = bn.Scope

其中bf.EmployeeId=15366这意味着bf.EmployeeId不能为null，其中仍然需要为true。如果bf.EmployeeId=15366的计算结果不为true，则不会显示该行。