SQL - 对别名进行算术表达式引用（以嵌套SELECT计算）

Question

在我的SQL查询中，我需要对位于嵌套选择中的别名进行基于别名的算法。

我的查询如下：

    SELECT P.EMPLOYEE_NO, EE.BASIC_SALARY,
    (SELECT SUM (NEW_ACTIVITY_VALUE) 
        FROM 
            (SELECT 
                 (CASE WHEN P.ACTIVITY_TYPE = '0' THEN (P.ACTIVITY_VALUE * (-1))
                    ELSE P.ACTIVITY_VALUE
                  END) AS NEW_ACTIVITY_VALUE
                FROM V_EMPLOYEE_PAYACT P
                WHERE P.ACTIVITY_TYPE IN ('0','1') AND P.EMPLOYEE_NO = '00002789' AND
                    ((YEAR = 2014 AND MONTH <= 4)
                    OR
                    (YEAR > 2013 AND YEAR <2014)
                    OR
                    (YEAR = 2013 AND MONTH >= 5)) 
                    ) t
        ) AS SUM_ACTIVITY_VALUE,
    (SELECT NEW_BASIC_SALARY FROM
            (SELECT (EE.BASIC_SALARY- SUM_ACTIVITY_VALUE) AS NEW_BASIC_SALARY 
                FROM EMPLOYEE_EMPLOYMENT EE
                ) AS X
FROM EMPLOYEE_EMPLOYMENT EE
JOIN V_EMPLOYEE_PAYACT P
ON EE.EMPLOYEE_ID = P.EMPLOYEE_ID
WHERE P.EMPLOYEE_NO = '00002789'
GROUP BY P.EMPLOYEE_NO, EE.BASIC_SALARY

我现在唯一的问题是这个部分：

..(SELECT NEW_BASIC_SALARY FROM
            (SELECT (EE.BASIC_SALARY- SUM_ACTIVITY_VALUE) AS NEW_BASIC_SALARY 
                FROM EMPLOYEE_EMPLOYMENT EE
                ) AS X...

如果我从查询中扣除上述有问题的部分，我得到的结果如下：
EMP_NO | s BASIC_SALARY | s SUM_ACTIVITY_VALUE | s
1234-S-S-S | 2009年-S-S-S-S-S-S-S | 100-S-S-S-S-S-S-S-S-S |

我需要的结果如下：
EMP_NO | s BASIC_SALARY | s SUM_ACTIVITY_VALUE | s NEW_BASIC_SALARY | s
1234-S-S-S | 2009年-S-S-S-S-S-S-S | 100-S-S-S-S-S-S-S-S-S-S-S | 1909年-S-S-S-S-S-S-S |

P / S：我很抱歉我的问题格式化，有点丢失了如何格式化表格。

Answer 1

您的查询中可能存在其他缺陷，但是如果您要获取要用功能查询减去的值，那么您可以简单地将整个事物作为子查询并使用别名进行减法。 ：

SELECT *,BASIC_SALARY - SUM_ACTIVITY_VALUE as NEW_BASIC_SALARY
FROM (
 SELECT P.EMPLOYEE_NO
      , EE.BASIC_SALARY
      ,(SELECT SUM (NEW_ACTIVITY_VALUE) 
        FROM (SELECT (CASE WHEN P.ACTIVITY_TYPE = '0' 
                            THEN (P.ACTIVITY_VALUE * (-1))
                            ELSE P.ACTIVITY_VALUE
                      END) AS NEW_ACTIVITY_VALUE
              FROM V_EMPLOYEE_PAYACT P
              WHERE P.ACTIVITY_TYPE IN ('0','1') 
                AND P.EMPLOYEE_NO = '00002789' 
                AND    ((YEAR = 2014 AND MONTH <= 4)
                    OR (YEAR > 2013 AND YEAR <2014)
                    OR (YEAR = 2013 AND MONTH >= 5)) 
              ) t
        ) AS SUM_ACTIVITY_VALUE
FROM EMPLOYEE_EMPLOYMENT EE
JOIN V_EMPLOYEE_PAYACT P
ON EE.EMPLOYEE_ID = P.EMPLOYEE_ID
WHERE P.EMPLOYEE_NO = '00002789'
GROUP BY P.EMPLOYEE_NO, EE.BASIC_SALARY
) sub