sp_xml_preparedocument 出现错误“在 XML 文档中只允许一个顶级元素”

Question

我正在尝试执行 sp_xml_preparedocument 并收到错误“在 XML 文档中只允许一个顶级元素”

我的 T-SQL 命令：

DECLARE @aa XML
DECLARE @idoc int
SET @aa =(select * from db_name for xml auto, xmldata) 

---

@aa 现在是

<Schema xmlns="urn:schemas-microsoft-com:xml-data" xmlns:dt="urn:schemas-microsoft-com:datatypes" name="Schema7">
<ElementType name="Person" content="empty" model="closed">
  <AttributeType name="preson_id" dt:type="i4" />
  <AttributeType name="Name" dt:type="string" />
  <AttributeType name="Surname" dt:type="string" />
  <AttributeType name="guid" dt:type="uuid" />
  <AttributeType name="version" dt:type="bin.base64" />
  <attribute type="preson_id" />
  <attribute type="Name" />
  <attribute type="Surname" />
  <attribute type="guid" />
  <attribute type="version" />
 </ElementType>
</Schema>
  <Person xmlns="x-schema:#Schema7" preson_id="1" Name="Иван" Surname="Иванов" guid="2E739E87-3CA4-4ED8-ADD0-8B59957668B8" version="AAAAAAAAB9E=" />
  <Person xmlns="x-schema:#Schema7" preson_id="2" Name="Николай" Surname="Николаев" guid="BDC41C59-D70F-4B70-954E-4918B9516AF8" version="AAAAAAAAB9I=" />
  <Person xmlns="x-schema:#Schema7" preson_id="3" Name="Максим" Surname="Максимов" guid="740E57F3-56BA-48B8-92AF-978D7B1D2712" version="AAAAAAAAB9M=" />

---

EXEC sp_xml_preparedocument @idoc OUTPUT, @aa

---

The XML parse error 0xc00ce555 occurred on line number 1, near the XML text ""
Msg 6602, Level 16, State 2, Procedure sp_xml_preparedocument, Line 1
The error description is 'Only one top level element is allowed in an XML document

---

我是新来的，我需要帮助))) 还有一个问题 - 如何解析时间戳类型？

如果我使用

SET @aa =(select * from db_name for xml elements, root('root'), type) 

sp_xml_preparedocument 工作正常，OPENXML 返回我的 db_table 的所有值，但时间戳值看起来与以前不同。

对不起我的英语不好

Answer 1

确保您尝试获取的记录没有重复条目

Answer 2

SELECT @aa 返回

<Schema xmlns="urn:schemas-microsoft-com:xml-data" xmlns:dt="urn:schemas-microsoft-com:datatypes" name="Schema7">
<ElementType name="Person" content="empty" model="closed">
  <AttributeType name="preson_id" dt:type="i4" />
  <AttributeType name="Name" dt:type="string" />
  <AttributeType name="Surname" dt:type="string" />
  <AttributeType name="guid" dt:type="uuid" />
  <AttributeType name="version" dt:type="bin.base64" />
  <attribute type="preson_id" />
  <attribute type="Name" />
  <attribute type="Surname" />
  <attribute type="guid" />
  <attribute type="version" />
 </ElementType>
</Schema>
  <Person xmlns="x-schema:#Schema7" preson_id="1" Name="Иван" Surname="Иванов" guid="2E739E87-3CA4-4ED8-ADD0-8B59957668B8" version="AAAAAAAAB9E=" />
  <Person xmlns="x-schema:#Schema7" preson_id="2" Name="Николай" Surname="Николаев" guid="BDC41C59-D70F-4B70-954E-4918B9516AF8" version="AAAAAAAAB9I=" />
  <Person xmlns="x-schema:#Schema7" preson_id="3" Name="Максим" Surname="Максимов" guid="740E57F3-56BA-48B8-92AF-978D7B1D2712" version="AAAAAAAAB9M=" />

Answer 3

一个 XML 文档必须只有一个根元素——参见W3C 规范。

因此，在您的情况下，如果 Schema 是根元素，则您不能在最后添加 Person 元素