JDBC Basics

1
JDBCBasics

• Not "Java DataBase Connectivity"

2
Overview

• Establishing a Connection
• Querying the Database
• Updating Tables

3
Loading Drivers

• Make sure you've loaded the drivers that came
  with the database!
• Oracle Driver
• Put this in your /lib directory
• Load driver in Java using the Class class
• Involves one line of code
• Examples
• Microsoft Access
• Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver")
• Oracle
• Class.forName ("oracle.jdbc.driver.OracleDriver")
  

4
Getting a Connection

• Use the DriverManager class to get the
  connection
• Connection connect
• String username "Bob"
• String passwd "6543216!"
• // Access
• String url "jdbcodbcmyDataBase"
• // Oracle
• String url "jdbcoraclethin_at_gandolf.ccsunet.cla
  yton.edu1521testDB"
• connect DriverManager.getConnection (url,
  username, passwd)

5
Creating a Statement

• A statement object is what sends your SQL
  statements to the DBMS
• Use the connection to create the statement
• Statement stmt connect.createStatement()
• stmt.executeUpdate ("CREATE TABLE STUDENTS (NAME
  VARCHAR(32), ID INTEGER, GRADE INTEGER)" )

6
Querying the DBSelect Statements

• A query returns a ResultSet
• Need to iterate through the results
• ResultSet rs stmt.executeQuery ( "SELECT NAME,
  ID FROM STUDENTS")
• while (rs.next( ))
• String s rs.getString ("Name")
• int i rs.getInt ("ID")

7

• import java.sql.
• class JDBKiller
• public static void main (String args)
• String driver "oracle.jdbc.driver.OracleDriver
  "
• String url "jdbcoraclethin_at_gandolf.ccsunet.
  clayton.edu1521test"
• String user "Bob"
• String passwd "theBuilder"
• Connection con null
• try
• Class.forName(driver)
• System.out.println("Driver loaded")
• con DriverManager.getConnection(url, user,
  passwd)
• con.close()
• catch (Exception e)
• System.out.println ("Failed...")
• System.out.println (e.getMessage())