Question

我正在尝试将多行值连接成单行...我已经达到了一个接近但是意识到下面的查询每次都错过了第一行......我在这里错过了一些明显的东西吗？我之前从未使用过CTE，所以我正在努力理解它背后的概念。提前谢谢。

WITH CTE ( AnswerResponseRefId, QuestionComponentList, QuestionComponentName, 
     templevel )
        AS ( 
            SELECT
            tao1.AnswerResponseRefId,
            CAST( '' AS VARCHAR(MAX) ) AS QuestionComponentList, 
            CAST( '' AS VARCHAR(69) )  AS QuestionComponentName, 
            0 AS templevel
            FROM
            TargetAnswersOrdered tao1
            WHERE tao1.QuestionRefId = 'B6944310-96FA-401C-86FE-A7BEA1D7B2B0'
            and tao1.TargetRefId = '5E013FC7-5AC9-45E4-A4D7-000F3C241599'
            GROUP BY tao1.AnswerResponseRefId

        UNION ALL

            SELECT          
                qc.AnswerResponseRefId,
                CAST( c.QuestionComponentList + 
                 CAST(c.QuestionComponentName AS VARCHAR(64)) AS VARCHAR(MAX) ),
                CAST( qc.QuestionComponentRefId AS VARCHAR(64)) + '*V' + 
                 CAST( qc.QuestionComponentVersion AS VARCHAR(2)) + '*',
                templevel + 1
            FROM CTE c

            INNER JOIN 

            TargetAnswersOrdered qc
            ON 
                c.AnswerResponseRefId = qc.AnswerResponseRefId 
            WHERE 
                CAST( qc.QuestionComponentRefId AS VARCHAR(64)) + '*V' + 
                CAST( qc.QuestionComponentVersion AS VARCHAR(2)) + '*' 
                    > c.QuestionComponentName
        )

SELECT 
    AnswerResponseRefId, 
    QuestionComponentList
FROM ( SELECT   
            AnswerResponseRefId, 
            QuestionComponentList, 
            RANK() OVER ( PARTITION BY 
                            AnswerResponseRefId 
                            ORDER BY templevel DESC )FROM CTE ) 
D ( AnswerResponseRefId, QuestionComponentList, rank )
    WHERE rank = 1 ;

Answer 1

解决..

在

中使用错误的参考号

CAST（c.QuestionComponentList + CAST（qc.QuestionComponentRefId AS VARCHAR（64））+' V'+ CAST（qc.QuestionComponentVersion AS VARCHAR（2））+''AS VARCHAR（MAX）））QuestionQonentList，

CTE连接在组迭代中缺少第一行

1 个答案: