ODBC and JDBC What are they – libraries of function calls that support SQL statements Why do we need them –Provide a way for an application to communicate with a database Why are they good –interoperability

ODBC (Open Database Connectivity) Application Driver Manager ODBC interface Driver A Driver B Driver C DS ADS B DS C

Adding an ODBC source Purpose: register a data source How-to (Windows 2000) –Start->Settings->Control Panel-> Administrative Tools->Data Sources(ODBC) NB: You need to register a new SQL server before you create the DSN

Further steps…. Select the System DSN tab Click add and choose SQL server (usually the bottom driver listed). Click Finish.

Further steps…. Chose identification entered by the user. Note: this is not the default option, so pay attention Enter the ID and password I gave you Agree with everything else in the wizard Test the data source and if your test succeeds, hit OK

JDBC (Java Database Connectivity) What is it: –Java classes that allow an app to communicate with a database Three types of JDBC drivers: –Proprietary –Bridge Drivers (e.g. JDBC-ODBC) –JDBC-Net

How does it work JDBC-ODBC bridge ODBC driver So, how does it work? You need to load the bridge driver and get a connection from the driver manager

Confusing? Let’s look at some code import java.sql.*; Class FirstTry{ public static void main(String[] args){ try{ String url=“jdbc:odbc:myDSN”; /*load the driver from Sun.Even if you don’t understand this, this line is always the same*/ Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”); //get a connection Connection con=DriverManager.getConnection(url,”userID”,”password”); }catch….

How does it fit together Note the DSN in the database url—it is the ODBC DSN JDBC is just a way for Java applications to do what ASP does with ODBC.

What next Well, just have fun. Check out Sun’s API for the sql package See Sun’s tutorial on JDBC

The Front End Web pages: static/dynamic Techniques for creating dynamic content : –CGI (Perl), ASP, JSP Requests, Responses and Headers –HTTP: simple, stateless. Client(I.e.browser) requests, web server responds Requests can be of several types(methods): usually GET and POST

ADO Set of objects to modify and access data through OLE DB interface: Connection, Command,Recordset,Error Application uses ADO which talks to OLE DB provider for ODBC, which loads the right ODBC driver. Note: providers represent diverse sources of data, pick the right one