JDBC Vs Java Blend Presentation by Gopal Manchikanti Shivakumar Balasubramanyam JDBC Technology INTRODUCTION Structured Query Language SQL Microsoft s ODBC Need for JDBC About JDBC SQL Used to Create Manipulate Examine and Manage Databases Application Specific Language Unsuitable as a General Application Language Another Language Needed for Visual Display and Report Generation ODBC Microsoft Product C Based Interface to SQL Based Databases Provides a consistent Interface for communicating WHY JDBC ODBC not appropriate for direct use from Java Translation of ODBC API into Java API Not Desirable ODBC is hard to Learn JDBC is needed to enable a pure Java solution JDBC Creates a Interface for communicating with Databases Based on the X Open SQL Call Level Interface Allows Reuse of Database Connections Connection Pooling Useful in Accessing data across incompatible DBMS JDBC Easy to Learn and Use Provides a truly portable solution to writing Database Applications Talk to a variety of Databases Maintain the Security Robustness and Portability JDBC Architecture JDBC API for Application Writers JDBC API for Driver Writers JDBC Two Tier and Three Tier Models JDBC URL s The JDBC API Establish a Connection with a Database java sql Environment allows creation of new database connections Send SQL statements java sql Statement container class for embedded SQL statements Process the results java sql ResultSet access control to results of a statement JDBC API Client Application GUI DataBase Sever JDBC API Network Interface SQL Results SQL Requests Network Connection SQL Results JDBC Drivers JDBC requires drivers to connect with individual Databases Types of Drivers 1 JDBC ODBC bridge 2 Partial Java Driver 3 Pure Java driver for database middle ware 4 Direct to database pure Java driver Two tier and Three tier Models JDBC supports both two tier and three tier models for database access Two tier Model Applet Application talks directly to the database Requires a JDBC driver that can communicate with the database Referred to as Client Server Configuration Client Server Model DataBase Sever Client Application GUI JDBC Driver Network Interface SQL Results Network Interface SQL Requests Network Connection SQL Results Two tier and Three tier Models Three tier Model Commands and Results sent to middle tier of services Attractive as it maintains control on the accesses and updates User can use a easy to use higher level API Middle tier implemented in Java gives advantages of Robustness Multithreading and Security features Three Tier Model Client DataBase Sever Application GUI JDBC Driver Cl Network Interface Network Interface Network A Network B MIDDLE WARE Network Interface Network Interface JDBC Driver ser Database Lib JDBC URL s Way of Identifying a database Appropriate Driver recognizes it and establishes a connection Allow driver writers to encode all necessary connection information Allow a level of indirection Standard syntax jdbc subprotocol subname Driver Manager DriverManager class maintains a list of Driver classes Driver classes need to register with the Driver Manager Registration is done automatically by the driver when it loaded Allows Keeping Track of Available Drivers Connecting Talking Processing A Connection Object represents a connection with a database A Connection Session includes Statements executed and Results got DriverManager getConnection Standard way to establish connection The method takes a string containing a URL DriverManager tries to use each of the drivers in the order of registration Connecting Talking Processing DriverManager tests the drivers by calling the Driver connect The first driver that recognizes the URL makes the connection Mechanism for reading and writing data between Java and SQL JDBC define a set of generic SQL type identifiers Dynamic Data Access SECURITY Issues Restriction from opening Network Connections DataBase needs to reside on the WebServer Key Features of JDBC Full Access to Metadata No Installation Database Connection Identified by URL Connection Pooling and Distributed Transactions Advantages of JDBC Leverage Existing Enterprise Data Simplified Enterprise Development Zero Configuration for Network Computers For e commerce applications running on the Internet Gives all advantages of Java like Portability Security and Robustness FURTHER Advancements JDBC is a base for Higher Level APIs Higher Level APIs on top of JDBC An embedded SQL for Java allows mixing SQL statements within Java Direct Mapping of Relational Database tables to Java classes Java Blend