C# 合并gridview行并消除重复项

我有两张桌子：

Table 1

id   question   customerId
1     bla1         1
2     bla2         2    

Table 2

id    customerId    Key         Value
1      1           firstname    John
2      1           lastname     Doe
3      2           firstname    Billy
4      2           lastname     Jones

我需要让我的gridview显示：

Row 1: John Doe        Bla1
Row 2: Billy Jones     Bla2

目前它显示：（但我不想这样）：

我想我什么都试过了，需要你的帮助！谢谢

SELECT  [firstname],[lastname], question
FROM
        (
            SELECT  a.question, b.[key], b.[value]
            FROM    Table1 a
                    INNER JOIN Table2 b
                        ON a.customerID = b.CustomerID
        ) org
        PIVOT
        (
            MAX([value])
            FOR [KEY] IN ([firstname],[lastname])
        ) pvt

输出

╔═══════════╦══════════╦══════════╗
║ FIRSTNAME ║ LASTNAME ║ QUESTION ║
╠═══════════╬══════════╬══════════╣
║ John      ║ Doe      ║ bla1     ║
║ Billy     ║ Jones    ║ bla2     ║
╚═══════════╩══════════╩══════════╝

---

使用以下查询选择绑定网格的数据：

SELECT 
    a.id, 
    a.Question,
    (SELECT Value + ' ' FROM Table2 b WHERE b.customerId=a.customerid 
        FOR XML PATH(''),type).value('.','nvarchar(max)') Value
FROM Table1 a

---

如果您想在SQL中解决这个问题，可能需要表表达式：+1表示SQL FIDLE。这很有趣：）我必须在我的数据库上创建要测试的结构。我正在使用gridview，但DataKeyNames=“Id”DataBinding:“System.Data.DataRowView”不包含名为“Id”的属性。“我为DataKeyNames放什么？不管怎样，我只是将DataKeyNames全部去掉。”。谢谢你的甜蜜解决方案。你一定是个天才！

SELECT [firstname],[lastname], question
FROM
(
    SELECT Q.ID, Question, Q.CUSTOMERID, KeyId, KeyValue 
    FROM QUESTION Q
            INNER JOIN CUSTOMERMAP C ON Q.CUSTOMERID=C.CUSTOMERID
) as Data
PIVOT
(
   MAX(KeyValue)
   FOR KeyId in ([firstname],[lastname])
) as PT;

SELECT 
    a.id, 
    a.Question,
    (SELECT Value + ' ' FROM Table2 b WHERE b.customerId=a.customerid 
        FOR XML PATH(''),type).value('.','nvarchar(max)') Value
FROM Table1 a