<all> 之间的区别<序列><选择>和<组>在 XSD 中?

何时使用 xsd:all, xsd:sequence, xsd:choice代码>，或 xsd:group:

When to use xsd:all, xsd:sequence, xsd:choice, or xsd:group:

• 当所有子元素都必须存在时使用 xsd:all订购.
• 使用 xsd:sequence 当子元素必须按照它们的顺序存在时发生限制和顺序很重要.
• 当必须存在子元素之一时使用 xsd:choice.
• 使用 xsd:group 作为包装上述任何一项的方式，以便命名并在 XSD 内的多个位置重复使用.

• Use xsd:all when all child elements must be present, independent of order.
• Use xsd:sequence when child elements must be present per their occurrence constraints and order does matters.
• Use xsd:choice when one of the child element must be present.
• Use xsd:group as a way to wrap any of the above in order to name and reuse in multiple locations within an XSD.

请注意，除了子元素之外，出现约束还可以出现在 xsd:all、xsd:sequence 或 xsd:choice 上实现各种基数效果.

Note that occurrence constraints can appear on xsd:all, xsd:sequence, or xsd:choice in addition to the child elements to achieve various cardinality effects.