如何在SQL查询中访问当前/相同/自行列值

问题：我有一些公司提交审计报告。我需要准备一个报告栏，根据两个条件显示下一个日期

如果任何FormF表格有多行，则从最新表格的结束日期起一年，即“ReportingTo”

如果只找到一个FormF记录，则自“注册日期”起一年

代码：

---

尽可能避免在select列中执行子查询

;WITH EntityCounts AS
(
    SELECT
        EntityID = F.EntityID,
        Amount = COUNT(1),
        LatestEndDate = MAX(F.ReportingTo)
    FROM
        [db_owner].[FormF] AS F
    GROUP BY
        F.EntityID
)
SELECT
    F.ID,
    E.[Title (Title)],
    F.ReportingFrom,
    F.ReportingTo,
    E.RegistrationDate,
    AuditDueDate = CASE
        WHEN C.Amount > 1 THEN DATEADD(YEAR, 1 C.LatestEndDate)
        ELSE DATEADD(YEAR, 1, E.RegistrationDate) END
FROM
    [db_owner].[FormF] AS F
    INNER JOIN EntityCounts AS C ON F.EntityID = C.EntityID
    INNER JOIN entity AS E ON F.EntityID = E.ID

---

对子查询使用不同的表别名，并查看最外面的where子句。我确实更改了别名，但结果相同。我也不明白你们对“审查”最外层where条款的评论。“AditDueDate”发布的查询预期结果应显示“2019年4月2日”您的where is

F.[EntityID]=F.[EntityID]

，这将说明显而易见的情况（在大多数情况下）。

;WITH EntityCounts AS
(
    SELECT
        EntityID = F.EntityID,
        Amount = COUNT(1),
        LatestEndDate = MAX(F.ReportingTo)
    FROM
        [db_owner].[FormF] AS F
    GROUP BY
        F.EntityID
)
SELECT
    F.ID,
    E.[Title (Title)],
    F.ReportingFrom,
    F.ReportingTo,
    E.RegistrationDate,
    AuditDueDate = CASE
        WHEN C.Amount > 1 THEN DATEADD(YEAR, 1 C.LatestEndDate)
        ELSE DATEADD(YEAR, 1, E.RegistrationDate) END
FROM
    [db_owner].[FormF] AS F
    INNER JOIN EntityCounts AS C ON F.EntityID = C.EntityID
    INNER JOIN entity AS E ON F.EntityID = E.ID