IBM Version 5 manual Restriction base=string length value=30 SimpleType Element

<restriction base="string"> <length value="30"/>

</restriction>

</simpleType>

</element>

<element name="AIRCRAFT"> <simpleType>

<restriction base="string"> <length value="10"/>

</restriction>

</simpleType>

</element>

<element name="DEPARTURE"> <simpleType>

<restriction base="string"> <length value="10"/>

</restriction>

</simpleType>

</element>

<element name="ARRIVAL"> <simpleType>

<restriction base="string"> <length value="10"/>

</restriction>

</simpleType>

</element>

</sequence>

</complexType>

</schema>

For the tables that we have used in our example, the schemas generated are quite simple. Here we generated a schema for the SCHEDULE table. The main element is named as SCHEDULE after the table, and our key here is just the flightNo. All the attributes within the table are held within a complexType element, the attributes themselves have been generated as elements. Notice that a <sequence> element has not been enforced on the order of the columns in the XML Schema.

In this example, the foreign key from the Aircraft column to the AIRCRAFT table has not been given any extra attention. It appears just like another column in the table. When a XML Schema is generated for the AIRCRAFT table, the XML Schema does not show any relationship with the SCHEDULE XML Schema.

An alternative to this method of generating a schema from a table would be to use a select statement. Looking at Figure 5.1, showing the Passenger List statement, one could create a select statement just on the SCHEDULE table.

124 The XML Files: Development of XML/XSL Applications Using WebSphere Studio