XML

Accessing SQL Server

You should now be able to access SQL Server in a URL that specifies HTTP as the protocol. Place the following query into the navigation bar in Internet Explorer 5 and get back the appropriate results:

  http://localhost/northwind?sql=SELECT+*+FROM+Customers+FOR+XML+AUTO

Figure 15-2 shows what this query returns.

Figure 15-2. The XML data returned from the query.

As you can see, this ISAPI extension allows you to rapidly and easily retrieve data from a SQL Server database. The format of the XML data can be specified in several ways by using the FOR XML clause in the SELECT statement. The FOR XML clause can specify one of the three modes: AUTO, RAW, and EXPLICIT. In Figure 152, we used the AUTO mode to allow the ISAPI extension to format the data as a nested tree. The RAW mode takes the query result and transforms each row in the result set into an XML element with a generic row identifier as the element tag. Figure 15-3 shows what the results would look like using the RAW mode.

Figure 15-3. Using the RAW mode in the query.

The EXPLICIT mode allows you to define the shape of the XML tree that is returned.

by BrainBellupdated
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