Quick start guide to accessing a SQL Anywhere HTTP web server

This quick start guide illustrates how to access a SQL Anywhere HTTP web server using two different types of client application - Python and C#. It does not illustrate SQL Anywhere web service application capabilities to a full extent. Many SQL Anywhere web service features are available that are beyond the scope of this guide.

The following tasks are performed:

Create a procedure that connects to a web service on an HTTP server.
Perform operations on the result set sent by the HTTP server.

You can develop SQL Anywhere web client applications that connect to any type of online web server, but this guide assumes that you have started a local SQL Anywhere HTTP server on port 8082 and want to connect to a web service named SampleWebService, created with the following SQL script:

CREATE SERVICE SampleWebService
    TYPE 'XML'
    USER DBA
    AUTHORIZATION OFF
    AS CALL sp_echo(:i, :f, :s);

CREATE PROCEDURE sp_echo(i INTEGER, f NUMERIC(6,2), s LONG VARCHAR )
RESULT( ret_i INTEGER, ret_f NUMERIC(6,2), ret_s LONG VARCHAR )
BEGIN
	SELECT i, f, s;
END;

For more information about setting up a quick HTTP server, see Quick start guide to using SQL Anywhere as an HTTP web server.

To access an XML web service using C# or Python

Write code that accesses the SampleWebService web service.

For C#, use the following code:

using System;
using System.Xml;

public class WebClient {
    static void Main(string[] args) {
        XmlTextReader reader = new XmlTextReader( "http://localhost:8082/demo/SampleWebService?i=5&f=3.14&s=hello" );

        while( reader.Read() ) {
            switch( reader.NodeType ) {
                case XmlNodeType.Element:
                    if( reader.Name == "row" ) {
                        Console.Write(reader.GetAttribute("ret_i") + " ");
                        Console.Write(reader.GetAttribute("ret_s") + " ");
                        Console.WriteLine(reader.GetAttribute("ret_f"));
                    }
                    break;
            }
        }
        reader.Close();
    }
}

Save the code to a file named DocHandler.cs.

To compile the program, run the following command at the command prompt:

csc /out:DocHandler.exe DocHandler.cs

For Python, use the following code:

import xml.sax

class DocHandler( xml.sax.ContentHandler ):
    def startElement( self, name, attrs ):
        if name == 'row':
            table_int = attrs.getValue( 'ret_i' )
            table_string = attrs.getValue( 'ret_s' )
            table_float = attrs.getValue( 'ret_f' )
            print '%s %s %s' % ( table_int, table_string, table_float )

parser = xml.sax.make_parser()
parser.setContentHandler( DocHandler() )
parser.parse( 'http://localhost:8082/demo/SampleWebService?i=5&f=3.14&s=hello' )

Save the code to a file named DocHandler.py.

Run the application.
- For C#, run the following command:
  DocHandler
- For Python, run the following command:
  python DocHandler.py

The application displays the following output:

5 hello 3.14

Quick start guide to accessing a SQL Anywhere HTTP web server

To access an XML web service using C# or Python

See also