database - Oracle 11g 查询中的标识符无效

Question

我有这个查询，在这行查询中我得到“ORA-00904: "RA"."TARGETRESOURCEID": invalid identifier':

t2.Id IN (SELECT TaskId FROM ResourceAssignment WHERE TargetResourceId = ra.TargetResourceId)

以下是完整的查询:

Select ra.TargetResourceId, 
(
  SELECT gn.Name FROM GeoNode gn WHERE gn.Id = 
  (
    SELECT t.StartPointId
    FROM Task t 
    WHERE t.Id = 
    (
      SELECT Id FROM
        (SELECT 
          t2.Id
        From 
          Task t2
        WHERE 
          t2.Id IN (SELECT TaskId FROM ResourceAssignment WHERE TargetResourceId = ra.TargetResourceId)
        ORDER BY 
          t2.StartTime1)
      WHERE rownum = 1 
    )
  ) 
) as DepartureNodeName
FROM 
  ResourceAssignment ra
INNER JOIN 
  Vehicle v ON v.Id = ra.SourceResourceId
INNER JOIN
  Unit u ON v.UnitId = u.Id
GROUP BY
    ra.TargetResourceId;

谁能确定问题所在，因为我找不到问题所在。

Answer 1

问题是来自外部查询的列只能在下一级子查询中访问。您正在尝试访问许多子查询级别下的外部查询列，因此您收到了该错误消息。

为避免错误，您需要重写查询，使您的子查询只有一层深 - 像这样(注意，未经测试，因为您没有提供任何示例数据等):

WITH assignment_info AS (SELECT ra.targetresourceid,
                                (SELECT MIN(t.startpointid) KEEP (dense_rank FIRST ORDER BY t.starttime1) task_startpointid
                                 FROM   task t
                                 WHERE  t.id = ra.targetresourceid) task_startpointid
                         FROM   resourceassignment ra
                         INNER  JOIN vehicle v
                         ON     v.id = ra.sourceresourceid
                         INNER  JOIN unit u
                         ON     v.unitid = u.id)
SELECT ai.targetresourceid,
       (SELECT gn.name
      FROM   geonode gn
      WHERE  gn.id = ai.task_startpointid) departurenodename
FROM   assignment_info;

我没有包含您的 GROUP BY ra.targetresourceid 子句，因为没有聚合，您的查询将因此失败。也许您打算在选择列表中使用 DISTINCT？