添加包含上一级父级的 cte 列

Posted 2023-02-19

【中文标题】添加包含上一级父级的 cte 列

【英文标题】：Add column with cte containing parent of one level up

【发布时间】：2013-10-12 23:22:29

【问题描述】：

我在 View 中有以下代码，它运行良好并提供所需的输出。

;WITH ctesample 
     AS (SELECT sjob, 
                mjob, 
                mjob AS DisplayMJob, 
                groupf, 
                0    AS LVL 
         FROM   dbo.vw_jobcosting_wipmastersub 
         WHERE  ( groupf = 'True' ) 
         UNION ALL 
         SELECT vw_JobCosting_WIPMasterSub_1.sjob, 
                vw_JobCosting_WIPMasterSub_1.mjob, 
                CASE S.lvl 
                  WHEN 0 THEN S.sjob 
                  ELSE S.displaymjob 
                END       AS DisplayMJob, 
                vw_JobCosting_WIPMasterSub_1.groupf, 
                S.lvl + 1 AS Expr1 
         FROM   ctesample AS S 
                INNER JOIN dbo.vw_jobcosting_wipmastersub AS 
                           vw_JobCosting_WIPMasterSub_1 
                        ON S.sjob = vw_JobCosting_WIPMasterSub_1.mjob 
         WHERE  ( vw_JobCosting_WIPMasterSub_1.groupf = 'False' )) 
SELECT sjob, 
       CASE 
         WHEN displaymjob IS NULL THEN sjob 
         ELSE displaymjob 
       END AS MJob, 
       groupf 
FROM   ctesample AS cteSample_1 

我需要再添加一列，为每条记录提供输出 MJob（而不是源数据 MJob）的父级。

源数据格式如下：

╔═════════════════════════╗
║ SJob,MJob,GroupF        ║
╠═════════════════════════╣
║ 10001000,NULL,True      ║
║ 10001001,NULL,True      ║
║ 10001002,NULL,True      ║
║ 20001000,10001000,True  ║
║ 20001001,10001001,True  ║
║ 20001002,10001001,True  ║
║ 20001003,10001002,True  ║
║ 30001000,20001000,False ║
║ 30001001,20001000,False ║
║ 30001002,20001001,False ║
║ 30001003,20001002,False ║
║ 30001004,20001002,False ║
║ 30001005,20001003,False ║
║ 30001006,20001003,False ║
║ 30001007,30001000,False ║
║ 30001008,30001000,False ║
║ 30001009,30001001,False ║
║ 30001010,30001002,False ║
║ 30001011,30001002,False ║
║ 30001012,30001003,False ║
║ 30001013,30001004,False ║
║ 30001014,30001005,False ║
║ 30001015,30001006,False ║
║ 30001016,30001006,False ║
╚═════════════════════════╝

我不知道如何解决。 建议将不胜感激。

需要的输出如下：

Sjob,Mjob,OutputMJob,GroupF
10001000,NULL,NULL,TRUE
10001001,NULL,NULL,TRUE
10001002,NULL,NULL,TRUE
20001000,10001000,NULL,TRUE
20001001,10001001,NULL,TRUE
20001002,10001001,NULL,TRUE
20001003,10001002,NULL,TRUE
30001000,20001000,10001000,FALSE
30001001,20001000,10001000,FALSE
30001002,20001001,10001001,FALSE
30001003,20001002,10001001,FALSE
30001004,20001002,10001001,FALSE
30001005,20001003,10001002,FALSE
30001006,20001003,10001002,FALSE
30001007,20001000,10001000,FALSE
30001008,20001000,10001000,FALSE
30001009,20001000,10001000,FALSE
30001010,20001001,10001001,FALSE
30001011,20001001,10001001,FALSE
30001012,20001002,10001001,FALSE
30001013,20001002,10001001,FALSE
30001014,20001003,10001002,FALSE
30001015,20001003,10001002,FALSE
30001016,20001003,10001002,FALSE

【问题讨论】：

数据库结构中的“输出 MJob 的父级”是什么意思？

【参考方案1】：

这个问题对我来说并不完全清楚，但据我了解，你想要这样的东西：

;WITH ctesample 
     AS (SELECT sjob, 
                mjob, 
                mjob AS DisplayMJob, 
                groupf, 
                0    AS LVL, 
                NULL outputMjob 
         FROM   dbo.vw_jobcosting_wipmastersub 
         WHERE  ( groupf = 'True' ) 
         UNION ALL 
         SELECT vw_JobCosting_WIPMasterSub_1.sjob, 
                vw_JobCosting_WIPMasterSub_1.mjob, 
                CASE S.lvl 
                  WHEN 0 THEN S.sjob 
                  ELSE S.displaymjob 
                END       AS DisplayMJob, 
                vw_JobCosting_WIPMasterSub_1.groupf, 
                S.lvl + 1 AS Expr1, 
                S.mjob 
         FROM   ctesample AS S 
                INNER JOIN dbo.vw_jobcosting_wipmastersub AS 
                           vw_JobCosting_WIPMasterSub_1 
                        ON S.sjob = vw_JobCosting_WIPMasterSub_1.mjob 
         WHERE  ( vw_JobCosting_WIPMasterSub_1.groupf = 'False' )) 
SELECT sjob, 
       CASE 
         WHEN displaymjob IS NULL THEN sjob 
         ELSE displaymjob 
       END AS MJob, 
       groupf, 
       outputmjob 
FROM   ctesample AS cteSample_1 

可以在SQL Fiddle 上找到一个工作示例。 如果这不是您所问的问题，请告诉我，我会尽力为您提供更好的答案。

【讨论】：

对不起，我不是很清楚。这接近我需要的，但并不完全。使用您的示例，OutputMJob 应该始终是 MJob 的父级。

那么你能尝试添加一些细节以便清楚吗？

我在表达我需要的东西时遇到了一点麻烦，我模拟了我所追求的输出。我希望这能让它更清楚一点。

@user2849560，在哪里模拟出来的？

抱歉，发到早了。在这里。