What is the difference between XSD choice and enumeration?

问题

What is the difference between XSD choice and enumeration?

回答1:

They are completely unrelated.

Choice indicates that within the content model of an element, you can use one of several child elements: for example within a document you have a choice of chapter or appendix as child elements.

Enumeration is used to restrict the values that can appear in a text or attribute node, for example to say that the value of a color attribute must be red, green, or blue.

回答2:

XSD choice allows you to choose between zero or one elements/attributes. These can be of any type.

Enumeration are used in XSD simpleTypes to either restrict or extend one particular type to a set of values.

回答3:

Gathering from the previous answers, and putting them together in clear, concise way:

The differences are two-fold:

• choice is for element tag, and enumeration is for a node's text or attribute.

• choice allows for zero instances, while enumeration requires one.

来源：https://stackoverflow.com/questions/5358132/what-is-the-difference-between-xsd-choice-and-enumeration