xml - msdata :Ordinal in an XSD? 的目的到底是什么

Question

我正在查看几个对序列中的元素使用 msdata:Ordinal 的 XSD 文件。我似乎无法在任何地方找到它的用途和/或在什么情况下需要它。有人可以帮我解释一下吗？

Answer 1

我也在想同样的事情。 xsd.exe 生成的 *.xsd 文件或使用 DataSet.WriteXmlSchema倾向于具有此属性，如“<VS folder>\Microsoft Visual Studio *\Xml\Schemas”文件夹中的 msdata.xsd 中所定义:

...
    <xs:attribute name="Ordinal" type="xs:integer">
    </xs:attribute>
...

该属性用于定义列的顺序位置，这对于将 xsd 模式映射到 DataSet 很有用。 .请参阅:Deriving DataSet Relational Structure from XML Schema (XSD) , Using XML in a DataSet

This article简单说一下:

An extra attribute named Ordinal has been created. As always, it is a part of the msdata space, with a value of 0 for the first column, and 1 for the second column. This is by virtue of each column being assigned a number starting with zero and then, progressively increasing it by one.