JDBC Tutorial

The JDBC ( Java Database Connectivity) API defines interfaces and classes for writing database applications in Java by making database connections. Using JDBC you can send SQL, PL/SQL statements to almost any relational database. JDBC is a Java API for executing SQL statements and supports basic SQL functionality. It provides RDBMS access by allowing you to embed SQL inside Java code. Because Java can run on a thin client, applets embedded in Web pages can contain downloadable JDBC code to enable remote database access. You will learn how to create a table, insert values into it, query the table, retrieve results, and update the table with the help of a JDBC Program example.
Although JDBC was designed specifically to provide a Java interface to relational databases, you may find that you need to write Java code to access non-relational databases as well.

JDBC Architecture

Java application calls the JDBC library. JDBC loads a driver which talks to the database. We can change database engines without changing database code.

JDBC Basics – Java Database Connectivity Steps

Before you can create a java jdbc connection to the database, you must first import the
java.sql package.
import java.sql.*; The star ( * ) indicates that all of the classes in the package java.sql are to be imported.
1. Loading a database driver,
In this step of the jdbc connection process, we load the driver class by calling Class.forName() with the Driver class name as an argument. Once loaded, the Driver class creates an instance of itself. A client can connect to Database Server through JDBC Driver. Since most of the Database servers support ODBC driver therefore JDBC-ODBC Bridge driver is commonly used.
The return type of the Class.forName (String ClassName) method is “Class”. Class is a class in
java.lang package.

try {
 Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); //Or any other driver
}
catch(Exception x){
 System.out.println( "Unable to load the driver class!" );
}

2. Creating a oracle jdbc Connection

The JDBC DriverManager class defines objects which can connect Java applications to a JDBC driver. DriverManager is considered the backbone of JDBC architecture. DriverManager class manages the JDBC drivers that are installed on the system. Its getConnection() method is used to establish a connection to a database. It uses a username, password, and a jdbc url to establish a connection to the database and returns a connection object. A jdbc Connection represents a session/connection with a specific database. Within the context of a Connection, SQL, PL/SQL statements are executed and results are returned. An application can have one or more connections with a single database, or it can have many connections with different databases. A Connection object provides metadata i.e. information about the database, tables, and fields. It also contains methods to deal with transactions.

JDBC URL Syntax::    jdbc: <subprotocol>: <subname>

JDBC URL Example:: jdbc: <subprotocol>: <subname>•Each driver has its own subprotocol
•Each subprotocol has its own syntax for the source. We’re using the jdbc odbc subprotocol, so the DriverManager knows to use the sun.jdbc.odbc.JdbcOdbcDriver.

try{
 Connection dbConnection=DriverManager.getConnection(url,"loginName","Password")
}
catch( SQLException x ){
 System.out.println( "Couldn't get connection!" );
}

3. Creating a jdbc Statement object,
Once a connection is obtained we can interact with the database. Connection interface defines methods for interacting with the database via the established connection. To execute SQL statements, you need to instantiate a Statement object from your connection object by using the createStatement() method.
Statement statement = dbConnection.createStatement();
A statement object is used to send and execute SQL statements to a database.
Three kinds of Statements
Statement: Execute simple sql queries without parameters.
Statement createStatement()
Creates an SQL Statement object.
Prepared Statement: Execute precompiled sql queries with or without parameters.
PreparedStatement prepareStatement(String sql)
returns a new PreparedStatement object. PreparedStatement objects are precompiled
SQL statements.
Callable Statement: Execute a call to a database stored procedure.
CallableStatement prepareCall(String sql)
returns a new CallableStatement object. CallableStatement objects are SQL stored procedure call statements.
4. Executing a SQL statement with the Statement object, and returning a jdbc resultSet.
Statement interface defines methods that are used to interact with database via the execution of SQL statements. The Statement class has three methods for executing statements:
executeQuery(), executeUpdate(), and execute(). For a SELECT statement, the method to use is executeQuery . For statements that create or modify tables, the method to use is executeUpdate. Note: Statements that create a table, alter a table, or drop a table are all examples of DDL
statements and are executed with the method executeUpdate. execute() executes an SQL
statement that is written as String object.
ResultSet provides access to a table of data generated by executing a Statement. The table rows are retrieved in sequence. A ResultSet maintains a cursor pointing to its current row of data. The next() method is used to successively step through the rows of the tabular results.
ResultSetMetaData Interface holds information on the types and properties of the columns in a ResultSet. It is constructed from the Connection object.

Test JDBC Driver Installation

import javax.swing.JOptionPane;

 public class TestJDBCDriverInstallation_Oracle {

    public static void main(String[] args) {
    StringBuffer output  = new StringBuffer();
    output.append("Testing oracle driver installation \n");
    try {
     String className = "sun.jdbc.odbc.JdbcOdbcDriver";
     Class driverObject = Class.forName(className);
     output.append("Driver : "+driverObject+"\n");
     output.append("Driver Installation Successful");
     JOptionPane.showMessageDialog(null, output);
      } catch (Exception e) {
       output  = new StringBuffer();
       output.append("Driver Installation FAILED\n");
       JOptionPane.showMessageDialog(null, output);
    System.out.println("Failed: Driver Error: " + e.getMessage());
    }
     }
 }

JDBC Sample Code

Java JDBC Connection Example, JDBC Driver Example

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.SQLException;

public class JDBCDriverInformation {
 static String userid="scott", password = "tiger";
 static String url = "jdbc:odbc:bob"; 

 static Connection con = null;
 public static void main(String[] args) throws Exception {
     Connection con = getOracleJDBCConnection();
     if(con!= null){
        System.out.println("Got Connection.");
        DatabaseMetaData meta = con.getMetaData();
        System.out.println("Driver Name : "+meta.getDriverName());
        System.out.println("Driver Version : "+meta.getDriverVersion());

     }else{
      System.out.println("Could not Get Connection");
     }
 }

 public static Connection getOracleJDBCConnection(){

  try {
   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); 

  } catch(java.lang.ClassNotFoundException e) {
   System.err.print("ClassNotFoundException: ");
   System.err.println(e.getMessage());
  }

  try {
     con = DriverManager.getConnection(url, userid, password);
  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }

  return con;
 }

}

JDBC Select Statement Example

Retrieving Data using JDBC Select Query

We can use Java JDBC Select statement in a java program to retrieve the data and display it for the respective Tables. JDBC returns results in a ResultSet object, so we need to declare an instance of the class ResultSet to hold our results. Select is the SQL keyword that performs a query. We invoke the jdbc select query (executequery) method, using the jdbc select data statement as the parameter. The tabular results of the query are captured in the ResultSet object, results. Note that executeQuery() always returns a ResultSet although it need not have any rows in it.
The return value for an executeQuery is a ResultSet object containing the results of the query sent to the DBMS,
To process each row in the ResultSet, we use the next() method. This method moves the pointer through the rows of data. The ResultSet maintains a cursor pointing to the current row. Because this cursor is initially positioned before the first row, we must call next() before we can see any rows at all. Below is a JDBC Program showing the use of executeQuery() to retrieve values from ResultSets using jdbc programming.
For my website I am creating the following 2 tables (Employee, Orders) as a part of the JDBC tutorial.
Employee_ID is the primary key which forms a relation between the 2 tables.
CREATE TABLE Employees (
Employee_ID INTEGER,
Name VARCHAR(30)
);
Employees Table:

Employee_ID	Name
100	Anil
101	Rahul
102	Arun
103	Niharika

Orders Table:
CREATE TABLE Orders (
Prod_ID INTEGER,
ProductName VARCHAR(20),
Employee_ID INTEGER
);

Prod_ID	Product Name	Employee_ID
543	Belt	100
432	Bottle	101
876	Ring	102

JDBC SQL Select Example

import javax.swing.JOptionPane;
import java.sql.*;
public class JDBCProgram{

 static String userid="scott", password = "tiger";
 static String url = "jdbc:odbc:bob"; // String url
= "jdbc:mySubprotocol:myDataSource"; ?
 static Statement stmt;
 static Connection con;
 public static void main(String args[]){

 JOptionPane.showMessageDialog(null,"JDBC Programming showi
ng Retrieval of Table Data");
  int choice = -1;

  do{
   choice = getChoice();
   if (choice != 0){
    getSelected(choice);
   }
  }
  while ( choice !=  0);
   System.exit(0);
 }

 public static int getChoice()
 {
  String choice;
  int ch;
  choice = JOptionPane.showInputDialog(null,
   "1. Create Employees Table\n"+
   "2. Create Products Table\n"+
   "3. Insert data into Employees Table\n"+
   "4. Insert data into Orders Table\n"+
   "5. Retrieve data for Employees Table\n"+
   "6.  Retrieve data for Orders Table\n"+
   "0. Exit\n\n"+
   "Enter your choice");
  ch = Integer.parseInt(choice);
  return ch;

 }

 public static void getSelected(int choice){
  if(choice==1){
   createEmployees();
  }
  if(choice==2){
   createOrders();
  }
  if(choice==3){
   insertEmployees();
  }
  if(choice==4){
   insertOrders();
  }
  if(choice==5){
   retrieveEmployees();
  }
  if(choice==6){
   retrieveOrders();
  }
 }

 public static Connection getConnection()
 {

  try {
   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
 //Class.forName("myDriver.ClassName"); ?

  } catch(java.lang.ClassNotFoundException e) {
   System.err.print("ClassNotFoundException: ");
   System.err.println(e.getMessage());
  }

  try {
   con = DriverManager.getConnection(url,
     userid, password);

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }

  return con;
 }

 /*CREATE TABLE Employees (
      Employee_ID INTEGER,
      Name VARCHAR(30)
  );*/

 public static void createEmployees()
 {
  Connection con = getConnection();

  String createString;
  createString = "create table Employees (" +
       "Employee_ID INTEGER, " +
       "Name VARCHAR(30))";
  try {
   stmt = con.createStatement();
      stmt.executeUpdate(createString);
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Employees Table Created");
 }

 /*CREATE TABLE Orders (
      Prod_ID INTEGER,
      ProductName VARCHAR(20),
      Employee_ID INTEGER
  );*/

 public static void createOrders()
 {
  Connection con = getConnection();

  String createString;
  createString = "create table Orders (" +
      "Prod_ID INTEGER, " +
      "ProductName VARCHAR(20), "+
      "Employee_ID INTEGER )";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(createString);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Orders Table Created");
 }

 /*Employee_ID  Name
   6323   Hemanth
   5768   Bob
   1234   Shawn
   5678   Michaels */
 public static void insertEmployees()
 {
  Connection con = getConnection();

  String insertString1, insertString2, insertString3, insertString4;
  insertString1 = "insert into Employees values(6323, 'Hemanth')";
  insertString2 = "insert into Employees values(5768, 'Bob')";
  insertString3 = "insert into Employees values(1234, 'Shawn')";
  insertString4 = "insert into Employees values(5678, 'Michaels')";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(insertString1);
      stmt.executeUpdate(insertString2);
      stmt.executeUpdate(insertString3);
      stmt.executeUpdate(insertString4);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Data Inserted into Employees Table");
 }

 /* Prod_ID  ProductName  Employee_ID
    543  Belt    6323
    432  Bottle    1234
    876  Ring   5678
 */
 public static void insertOrders()
 {
  Connection con = getConnection();

  String insertString1, insertString2, insertString3, insertString4;
  insertString1 = "insert into Orders values(543, 'Belt', 6323)";
  insertString2 = "insert into Orders values(432, 'Bottle', 1234)";
  insertString3 = "insert into Orders values(876, 'Ring', 5678)";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(insertString1);
      stmt.executeUpdate(insertString2);
      stmt.executeUpdate(insertString3);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Data Inserted into Orders Table");
 }

 public static void retrieveEmployees(){
  Connection con = getConnection();
  String result = null;
  String selectString;
  selectString = "select * from Employees";
     result ="Employee_ID\t\tName\n";
  try {
   stmt = con.createStatement();
   ResultSet rs = stmt.executeQuery(selectString);
   while (rs.next()) {
       int id = rs.getInt("Employee_ID");
       String name = rs.getString("Name");
       result+=id+"\t\t"+ name+"\n";
   }
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null, result);
 }

 public static void retrieveOrders(){
  Connection con = getConnection();
  String result = null;
  String selectString;
  selectString = "select * from Orders";
  result ="Prod_ID\t\tProductName\t\tEmployee_ID\n";
  try {
   stmt = con.createStatement();
   ResultSet rs = stmt.executeQuery(selectString);
   while (rs.next()) {
    int pr_id = rs.getInt("Prod_ID");
    String prodName = rs.getString("ProductName");
       int id = rs.getInt("Employee_ID");
       result +=pr_id+"\t\t"+ prodName+"\t\t"+id+"\n";
   }
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null, result);
 }

}//End of class

JDBC Update Table Example

We can use java jdbc update statements in a java program to update the data for a Table.
Below is a program showing the use of jdbc executeupdate (uses jdbc update query) to update a table.
The return value for a jdbc sql update is an int that indicates how many rows of a table
were updated.
For instance in a statement like
int n = stmt.executeUpdate();
For my website I am creating the following 2 tables (Employee, Orders) as a part of the JDBC update table statement.
Employee_ID is the primary key which forms a relation between the 2 tables.
CREATE TABLE Employees (
Employee_ID INTEGER,
Name VARCHAR(30)
);
Employees:

Employee_ID	Name
6323	Hemanth
5768	Bob
1234	Shawn
5678	Michaels

Orders:
CREATE TABLE Orders (
Prod_ID INTEGER,
ProductName VARCHAR(20),
Employee_ID INTEGER
);

Prod_ID	Product Name	Employee_ID
543	Belt	6323
432	Bottle	1234
876	Ring	5678

Below is a jdbc update example

import javax.swing.JOptionPane;
import java.sql.*;
public class JDBCProgram{

static String userid="scott", password = "tiger";
static String url = "jdbc:odbc:bob";
// String url = "jdbc:mySubprotocol:myDataSource"; ?
static Statement stmt;
static Connection con;
public static void main(String args[]){

JOptionPane.showMessageDialog
(null,"JDBC Programming showing Updation of Table Data");
  int choice = -1;

  do{
   choice = getChoice();
   if (choice != 0){
    getSelected(choice);
   }
  }
  while ( choice !=  0);
   System.exit(0);
 }

 public static int getChoice()
 {
  String choice;
  int ch;
  choice = JOptionPane.showInputDialog(null,
   "1. Create Employees Table\n"+
   "2. Create Products Table\n"+
   "3. Insert data into Employees Table\n"+
   "4. Insert data into Orders Table\n"+
   "5. Retrieve data for Employees Table\n"+
   "6. Retrieve data for Orders Table\n"+
   "7. Update Employees Table\n"+
   "0. Exit\n\n"+
   "Enter your choice");
  ch = Integer.parseInt(choice);
  return ch;

 }

 public static void getSelected(int choice){
  if(choice==1){
   createEmployees();
  }
  if(choice==2){
   createOrders();
  }
  if(choice==3){
   insertEmployees();
  }
  if(choice==4){
   insertOrders();
  }
  if(choice==5){
   retrieveEmployees();
  }
  if(choice==6){
   retrieveOrders();
  }
  if(choice==7){
   updateEmployees(); //Uses JDBC Update Statement
  }
 }

 public static Connection getConnection()
 {

  try {
 Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
 //Class.forName("myDriver.ClassName"); ?

  } catch(java.lang.ClassNotFoundException e) {
   System.err.print("ClassNotFoundException: ");
   System.err.println(e.getMessage());
  }

  try {
   con = DriverManager.getConnection(url,
    userid, password);

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }

  return con;
 }

 /*CREATE TABLE Employees (
      Employee_ID INTEGER,
      Name VARCHAR(30)
  );*/

 public static void createEmployees()
 {
  Connection con = getConnection();

  String createString;
  createString = "create table Employees (" +
       "Employee_ID INTEGER, " +
       "Name VARCHAR(30))";
  try {
   stmt = con.createStatement();
      stmt.executeUpdate(createString);
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
JOptionPane.showMessageDialog(null,"Employees Table Created");
 }

 /*CREATE TABLE Orders (
      Prod_ID INTEGER,
      ProductName VARCHAR(20),
      Employee_ID INTEGER
  );*/

 public static void createOrders()
 {
  Connection con = getConnection();

  String createString;
  createString = "create table Orders (" +
      "Prod_ID INTEGER, " +
      "ProductName VARCHAR(20), "+
      "Employee_ID INTEGER )";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(createString);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
JOptionPane.showMessageDialog(null,"Orders Table Created");
 }

 /*Employee_ID  Name
   6323   Hemanth
   5768   Bob
   1234   Shawn
   5678   Michaels */
 public static void insertEmployees()
 {
  Connection con = getConnection();

  String insertString1, insertString2, insertString3, insertString4;
  insertString1 = "insert into Employees values(6323, 'Hemanth')";
  insertString2 = "insert into Employees values(5768, 'Bob')";
  insertString3 = "insert into Employees values(1234, 'Shawn')";
  insertString4 = "insert into Employees values(5678, 'Michaels')";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(insertString1);
      stmt.executeUpdate(insertString2);
      stmt.executeUpdate(insertString3);
      stmt.executeUpdate(insertString4);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
JOptionPane.showMessageDialog(null,"Data Inserted into Employees Table");
 }

 /* Prod_ID  ProductName  Employee_ID
    543  Belt    6323
    432  Bottle    1234
    876  Ring   5678
 */
 public static void insertOrders()
 {
  Connection con = getConnection();

  String insertString1, insertString2, insertString3, insertString4;
  insertString1 = "insert into Orders values(543, 'Belt', 6323)";
  insertString2 = "insert into Orders values(432, 'Bottle', 1234)";
  insertString3 = "insert into Orders values(876, 'Ring', 5678)";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(insertString1);
      stmt.executeUpdate(insertString2);
      stmt.executeUpdate(insertString3);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
JOptionPane.showMessageDialog(null,"Data Inserted into Orders Table");
 }

 public static void retrieveEmployees(){
  Connection con = getConnection();
  String result = null;
  String selectString;
  selectString = "select * from Employees";
     result ="Employee_ID\t\tName\n";
  try {
   stmt = con.createStatement();
   ResultSet rs = stmt.executeQuery(selectString);
   while (rs.next()) {
       int id = rs.getInt("Employee_ID");
       String name = rs.getString("Name");
       result+=id+"\t\t"+ name+"\n";
   }
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
JOptionPane.showMessageDialog(null, result);
 }

 public static void retrieveOrders(){
  Connection con = getConnection();
  String result = null;
  String selectString;
  selectString = "select * from Orders";
  result ="Prod_ID\t\tProductName\t\tEmployee_ID\n";
  try {
   stmt = con.createStatement();
   ResultSet rs = stmt.executeQuery(selectString);
   while (rs.next()) {
    int pr_id = rs.getInt("Prod_ID");
    String prodName = rs.getString("ProductName");
       int id = rs.getInt("Employee_ID");
       result +=pr_id+"\t\t"+ prodName+"\t\t"+id+"\n";
   }
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
JOptionPane.showMessageDialog(null, result);
 }

 public static void updateEmployees(){
  Connection con = getConnection();

String updateString1;
updateString1 = "update Employees set name = 'hemanthbalaji'
where Employee_id = 6323";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(updateString1);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
JOptionPane.showMessageDialog(null,"Data Updated into Employees Table");
 }

}//End of class

Java Prepared Statements

Java JDBC Prepared statements are pre-compiled SQL statements. Precompiled SQL is useful if the same SQL is to be executed repeatedly, for example, in a loop. Prepared statements in java only save you time if you expect to execute the same SQL over again. Every java sql prepared statement is compiled at some point. To use a java preparedstatements, you must first create a object by calling the Connection.prepareStatement() method. JDBC PreparedStatements are useful especially in situations where you can use a for loop or while loop to set a parameter to a succession of values. If you want to execute a Statement object many times, it normally reduces execution time to use a PreparedStatement object instead.

The syntax is straightforward: just insert question marks for any parameters that you’ll be substituting before you send the SQL to the database. As with CallableStatements, you need to call close() to make sure database resources are freed as soon as possible. Below is a JDBC Program showing the use of jdbc prepared statements to insert data into tables using jdbc programming.
You need to supply values to be used in place of the question mark placeholders (if there are any) before you can execute a PreparedStatement object. You do this by calling one of the setXXX methods defined in the PreparedStatement class. There is a setXXX method for each primitive type declared in the Java programming language.
An example of a PreparedStatement object is
PreparedStatement pstmt = con.prepareStatement(“update Orders set pname = ? where Prod_Id = ?”);
pstmt.setInt(2, 100);
pstmt.setString(1, “Bob”);
pstmt.executeUpdate();
An important feature of a PreparedStatement object is that, unlike a Statement object, it is given an SQL statement when it is created. This SQL statement is sent to the DBMS right away, where it is compiled. As a result, the PreparedStatement object contains not just an SQL statement, but an SQL statement that has been precompiled. This means that when the PreparedStatement is executed, the DBMS can just run the PreparedStatement SQL statement without having to compile it first.
Using Prepared Statements in jdbc, objects can be used for SQL statements with no parameters, you probably use them most often for SQL statements that take parameters. The advantage of using SQL statements that take parameters is that you can use the same statement and supply it with different values each time you execute it.
For my website I am creating the following 2 tables (Employee, Orders) as a part of the JDBC tutorial.
Employee_ID is the primary key which forms a relation between the 2 tables
CREATE TABLE Employees (
Employee_ID INTEGER,
Name VARCHAR(30)
);
Employees:

Employee_ID	Name
6323	Hemanth
5768	Bob
1234	Shawn
5678	Michaels

Orders:
CREATE TABLE Orders (
Prod_ID INTEGER,
ProductName VARCHAR(20),
Employee_ID INTEGER
);

Prod_ID	Product Name	Employee_ID
543	Belt	6323
432	Bottle	1234
876	Ring	5678

Java JDBC Prepared Statement Example

import javax.swing.JOptionPane;
import java.sql.*;
public class JDBCProgram{

 static String userid="scott", password = "tiger";
 static String url = "jdbc:odbc:bob"
; // String url = "jdbc:mySubprotocol:myDataSource"; ?
 static Statement stmt;
 static PreparedStatement pstmt;
 static Connection con;
 public static void main(String args[]){

 JOptionPane.showMessageDial
og(null,"JDBC Programming showing Updation of Table Data");
  int choice = -1;

  do{
   choice = getChoice();
   if (choice != 0){
    getSelected(choice);
   }
  }
  while ( choice !=  0);
   System.exit(0);
 }

 public static int getChoice()
 {
  String choice;
  int ch;
  choice = JOptionPane.showInputDialog(null,
 "1. Create Employees Table\n"+
 "2. Create Products Table\n"+
 "3. Insert data into Employees Table\n"+
 "4. Insert data into Orders Table\n"+
 "5. Retrieve data for Employees Table\n"+
 "6. Retrieve data for Orders Table\n"+
 "7. Update Employees Table\n"+
 "8. Update Employees Table Using a Prepared Statement\n"+
 "9. Update many records of Orders Table Using a Prepared Statement\n"+
 "10. List the name of employees who bought CD'sn"+
   "0. Exit\n\n"+
   "Enter your choice");
  ch = Integer.parseInt(choice);
  return ch;

 }

 public static void getSelected(int choice){
  if(choice==1){
   createEmployees();
  }
  if(choice==2){
   createOrders();
  }
  if(choice==3){
   insertEmployees();
  }
  if(choice==4){
   insertOrders();
  }
  if(choice==5){
   retrieveEmployees();
  }
  if(choice==6){
   retrieveOrders();
  }
  if(choice==7){
   updateEmployees();
  }
  if(choice==8){
   updateEmployeesPrepared();
  }
  if(choice==9){
   updateOrdersPrepared();
  }
  if(choice==10){
   dynamicQuery();
  }
 }

 public static Connection getConnection()
 {

  try {
 Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
//Class.forName("myDriver.ClassName"); ?

  } catch(java.lang.ClassNotFoundException e) {
   System.err.print("ClassNotFoundException: ");
   System.err.println(e.getMessage());
  }

  try {
   con = DriverManager.getConnection(url,
   userid, password);

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }

  return con;
 }

 /*CREATE TABLE Employees (
      Employee_ID INTEGER,
      Name VARCHAR(30)
  );*/

 public static void createEmployees()
 {
  Connection con = getConnection();

  String createString;
  createString = "create table Employees (" +
      "Employee_ID INTEGER, " +
      "Name VARCHAR(30))";
  try {
   stmt = con.createStatement();
      stmt.executeUpdate(createString);
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Employees Table Created");
 }

 /*CREATE TABLE Orders (
      Prod_ID INTEGER,
      ProductName VARCHAR(20),
      Employee_ID INTEGER
  );*/

 public static void createOrders()
 {
  Connection con = getConnection();

  String createString;
  createString = "create table Orders (" +
      "Prod_ID INTEGER, " +
      "ProductName VARCHAR(20), "+
      "Employee_ID INTEGER )";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(createString);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Orders Table Created");
 }

 /*Employee_ID  Name
   6323   Hemanth
   5768   Bob
   1234   Shawn
   5678   Michaels */
 public static void insertEmployees()
 {
  Connection con = getConnection();

   String insertString1, insertString2, insertString3, insertString4;
   insertString1 = "insert into Employees values(6323, 'Hemanth')";
   insertString2 = "insert into Employees values(5768, 'Bob')";
   insertString3 = "insert into Employees values(1234, 'Shawn')";
   insertString4 = "insert into Employees values(5678, 'Michaels')";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(insertString1);
      stmt.executeUpdate(insertString2);
      stmt.executeUpdate(insertString3);
      stmt.executeUpdate(insertString4);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Data Inserted into Employees Table");
 }

 /* Prod_ID  ProductName  Employee_ID
    543  Belt    6323
    432  Bottle    1234
    876  Ring   5678
 */
 public static void insertOrders()
 {
  Connection con = getConnection();

   String insertString1, insertString2, insertString3, insertString4;
   insertString1 = "insert into Orders values(543, 'Belt', 6323)";
   insertString2 = "insert into Orders values(432, 'Bottle', 1234)";
   insertString3 = "insert into Orders values(876, 'Ring', 5678)";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(insertString1);
      stmt.executeUpdate(insertString2);
      stmt.executeUpdate(insertString3);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Data Inserted into Orders Table");
 }

 public static void retrieveEmployees(){
  Connection con = getConnection();
  String result = null;
  String selectString;
  selectString = "select * from Employees";
     result ="Employee_ID\t\tName\n";
  try {
   stmt = con.createStatement();
   ResultSet rs = stmt.executeQuery(selectString);
   while (rs.next()) {
       int id = rs.getInt("Employee_ID");
       String name = rs.getString("Name");
       result+=id+"\t\t"+ name+"\n";
   }
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null, result);
 }

 public static void retrieveOrders(){
  Connection con = getConnection();
  String result = null;
  String selectString;
  selectString = "select * from Orders";
  result ="Prod_ID\t\tProductName\t\tEmployee_ID\n";
  try {
   stmt = con.createStatement();
   ResultSet rs = stmt.executeQuery(selectString);
   while (rs.next()) {
    int pr_id = rs.getInt("Prod_ID");
    String prodName = rs.getString("ProductName");
       int id = rs.getInt("Employee_ID");
       result +=pr_id+"\t\t"+ prodName+"\t\t"+id+"\n";
   }
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null, result);
 }

 public static void updateEmployees(){
  Connection con = getConnection();

  String updateString1;
  updateString1 = "update Employees set name = 'hemanthbalaji'
 where Employee_id = 6323";

  try {
   stmt = con.createStatement();
      stmt.executeUpdate(updateString1);

   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Data Updated into Employees Table");
 }

 public static void updateEmployeesPrepared(){
  Connection con = getConnection();
// create prepared statement
  try {
 pstmt = con.prepareStatement
("update Employees set name = ? where Employee_Id  = ?");
 pstmt.setString(1, "hemanthbob"); //Note index starts with 1
 pstmt.setInt(2, 6323);

      pstmt.executeUpdate();

   pstmt.close();
   con.close();

  } catch(SQLException ex) {
     System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Data Updated into Employees Table");
 }

 public static void updateOrdersPrepared(){

  int [] productIds = {543, 432, 876};
  String [] productNames = {"cds", "dvds", "Espresso"};
  int len = productNames.length;

  Connection con = getConnection();

  try {
 pstmt = con.prepareStatement
("update Orders set productname = ? where Prod_Id  = ?");
   for(int i = 0; i < len; i++) {
    pstmt.setInt(2, productIds[i]);
    pstmt.setString(1, productNames[i]);
    pstmt.executeUpdate();
   }

   pstmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null,"Data Updated into Orders Table");
 }

 public static void dynamicQuery(){
  Connection con = getConnection();
  String result = null;
  String selectString;
  selectString = "select Employees.name from Employees,
Orders where productname = 'cds' " +
   "and Employees.employee_id = Orders.employee_id ";
     result ="Name\n";
  try {
   stmt = con.createStatement();
   ResultSet rs = stmt.executeQuery(selectString);
   while (rs.next()) {
       String name = rs.getString("Name");
       result+=name+"\n";
   }
   stmt.close();
   con.close();

  } catch(SQLException ex) {
   System.err.println("SQLException: " + ex.getMessage());
  }
 JOptionPane.showMessageDialog(null, result);
 }

}//End of class

Also, please remember leave a comment if there’s anything I should do to improve this. Thank you!