Sql 子查询中的Oracle标识符无效

我有一个问题：

SELECT
    XMLELEMENT("row", XMLATTRIBUTES(productMain.variant as "order"),
        (SELECT XMLELEMENT("attribute", XMLATTRIBUTES(product.id as "id") )
        FROM product where product.variant = productMain.variant
        )
    )

FROM
    (SELECT 
        DISTINCT product.variant 
    FROM 
        product
    WHERE
        product.fk_parent = 12345) productMain

我得到一个错误“无效标识符

productMain.variant

”

预期结果：

<row order="1">
    <attribute name="Example1"/>
    <attribute name="Example2"/>
    ...
</row>
<row order="2">
    ...
</row>

id | variant | name
_________________________
1  | 1       | Example1
2  | 1       | Example2
3  | 2       | Example3
4  | 3       | Example4
5  | 3       | Example5

SQLFIDDLE:

我发现，Oracle不会将嵌套在多个级别的子查询关联起来

如何仍然获得我想要的结果？

解决方案：

SELECT
XMLELEMENT("row", XMLATTRIBUTES(productMain.variant as "order"),
    (SELECT XMLELEMENT("attribute", XMLATTRIBUTES(product.id as "id") )
    FROM product,
    (SELECT DISTINCT variant FROM 
    product
    WHERE fk_parent = 12345) as productMain 
    where product.variant = productMain.variant
    )
)

FROM
(SELECT 
    DISTINCT variant 
FROM 
    product
WHERE
    fk_parent = 12345) productMain

SELECT
XMLELEMENT("row", XMLATTRIBUTES(productMain.variant as "order"),

  (
  SELECT 
    XMLAGG(XMLELEMENT("attribute",XMLATTRIBUTES(product.name as "name"),product.variant)) FROM product 
    where product.fk_parent = 12345
    and product.variant = productmain.variant
  )

).getClobVal()

FROM
(SELECT 
    DISTINCT product.variant 
FROM 
    product
WHERE
    product.fk_parent = 12345) productMain;

---

您的表名和别名非常混乱，请修复。抱歉@Colin'tHart。现在已修复。差不多了，请也修复错误消息：是

product.variant

还是

productMain.variant

在那里？是的，它的“productMain.variant”。它不知道另一个子选择的值。Oracle不关联嵌套了多个级别的子查询。单行子查询返回多行