The XML files we have worked with so far were straightforward and only dealt with a single collection of elements. However, many systems produce or consume XML files that contain multiple collections of elements; these are called multi-schema XML files. Here's an example:
<?xml version="1.0" encoding="UTF-8"?>
<catalogue>
<skus>
<sku>
<skuid>432345</skuid>
<skuname>Check Shirt</skuname>
<size>S</size>
<colour>Green</colour>
<price>29.99</price>
</sku>
</skus>
<inventory>
<sku>
<skuid>432345</skuid>
<stock_on_hand>12</stock_on_hand>
</sku>
</inventory>
</catalogue>This shows a product catalogue file with two schemas, one for the product details and one for the inventory. There's nothing in the XML structure to connect the two schemas. In essence...