Java JDBC tutorial

1- Database used in this document

This document guide you how to use interactive Java with database.
The Database model used in this document is  "simplehr". You can see scripts of creating database at:

2- What is JDBC?

Java Database Connectivity ( JDBC) is a standard Java API to interact with relational databases form Java. JDBC has set of classes and interfaces which can use from Java application and talk to database without learning RDBMS details and using Database Specific JDBC Drivers.
The components of JDBC Api basically include:
  1. DriverManager:
    • Manages a list of database drivers. Matches connection requests from the java application with the proper database driver using communication subprotocol. The first driver that recognizes a certain subprotocol under JDBC will be used to establish a database Connection.
  2. Driver:
    • The database communications link, handling all communication with the database. Normally, once the driver is loaded, the developer need not call it explicitly.
  3. Connection :
    • Interface with all methods for contacting a database.The connection object represents communication context, i.e., all communication with database is through connection object only.
  4. Statement :
    • Encapsulates an SQL statement which is passed to the database to be parsed, compiled, planned and executed.
  5. ResultSet:
    • The ResultSet represents set of rows retrieved due to query execution.

3- How to connect java with database

Java using JDBC to work with the database.
For example, when working with Oracle Database from Java you need to have a Driver (It is a class driving the connection with types of database you want). In JDBC API, we have   java.sql.Driver, it is only an interface and it is available in JDK. Thus, you have to download library Driver compatible with the type of Database you want.
  • For example, with Oracle, the class implements the Interface java.sql.Driver is oracle.jdbc.driver.OracleDriver
java.sql.DriverManager is a class in  JDBC API. It is responsible for managing Drivers.
Please see the illustration below:
We have two manners to work with a particular database.
  • Manner 1: You provide Library Driver of that type of database, this is the direct manner. If you use DB oracle (or other DB), you will have to download the specific JDBC library of this DB.
  • Manner 2: Declare an "ODBC DataSource", and use the JDBC-ODBC Bridge for connecting with that "ODBC DataSource". The JDBC-ODBC Bridge is available in JDBC API.
The question for us is that what  "ODBC DataSource" is.

ODBC - Open Database Connectivity: It is a set of open libraries that are able to connect to almost all types of various database, and it is free. It is provided by Microsoft.

ODBC DataSource: On Window operating system, you can declare an ODBC connection to some DB type. As a result, we have a Data Source.

In the JDBC API, a JDBC-ODBC Bridge has been set up so that JDBC can exchange with ODBC.
As for speed, the first manner is faster than the second one, because the second one has to use bridge.

4- Download JDBC Driver

If you do not want to use  JDBC-ODBC, you can directly connect with Database. In this case, you need to download the Driver compatible with each DB type. Here I instruct you to download a type of Driver for common Database: 
  • Oracle
  • MySQL
  • SQLServer
  • ....
You can see instructions at:
The result we have a few files:

5- Create project to start with JDBC

Create project JavaJdbcTutorial:
Create libs folder on project, copy libraries and connected them directly with types of database  Oracle, MySQL, SQLServer you have just download. You can copy the whole or one of these libraries compatible with the DB type you use.

Note: You just need to download a Driver equivalent to the type of Database you are familiar to. You can get the Database used as the example in this document at:

Right-click and select Properties Project:
Now you are ready to work with one of Database:

6- Connection

In this instruction document, I will instruct you to connect to all three types of database:...
  • MySQL
  • SQLServer
  • Oracle
Into practice, you just need work with the DB type you feel familiar to.
Create utility class ConnectionUtils to get Connection
ConnectionUtils.java
package org.o7planning.tutorial.jdbc;

import java.sql.Connection;
import java.sql.SQLException;

public class ConnectionUtils {

    public static Connection getMyConnection() throws SQLException,
            ClassNotFoundException {
  
        // Using Oracle
        // You may be replaced by other Database.
        return OracleConnUtils.getOracleConnection();
    }

    //
    // Test Connection ...
    //
    public static void main(String[] args) throws SQLException,
            ClassNotFoundException {

        System.out.println("Get connection ... ");

        // Get a Connection object
        Connection conn = ConnectionUtils.getMyConnection();

        System.out.println("Get connection " + conn);

        System.out.println("Done!");
    }

}
OracleConnUtils.java
package org.o7planning.tutorial.jdbc;

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

public class OracleConnUtils {

    // Connect to Oracle.
    public static Connection getOracleConnection() throws SQLException,
            ClassNotFoundException {
        String hostName = "localhost";
        String sid = "db11g";
        String userName = "simplehr";
        String password = "1234";

        return getOracleConnection(hostName, sid, userName, password);
    }

    public static Connection getOracleConnection(String hostName, String sid,
            String userName, String password) throws ClassNotFoundException,
            SQLException {
       
        // Declare the class Driver for ORACLE DB
        // This is necessary with Java 5 (or older)
        // Java6 (or newer) automatically find the appropriate driver.
        // If you use Java> 5, then this line is not needed.        
        Class.forName("oracle.jdbc.driver.OracleDriver");

        String connectionURL = "jdbc:oracle:thin:@" + hostName + ":1521:" + sid;

        Connection conn = DriverManager.getConnection(connectionURL, userName,
                password);
        return conn;
    }
}
MySQLConnUtils.java
package org.o7planning.tutorial.jdbc;

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

public class MySQLConnUtils {


   // Connect to MySQL
   public static Connection getMySQLConnection() throws SQLException,
           ClassNotFoundException {
       String hostName = "localhost";

       String dbName = "simplehr";
       String userName = "root";
       String password = "1234";

       return getMySQLConnection(hostName, dbName, userName, password);
   }

   public static Connection getMySQLConnection(String hostName, String dbName,
           String userName, String password) throws SQLException,
           ClassNotFoundException {
       // Declare the class Driver for MySQL DB
       // This is necessary with Java 5 (or older)
       // Java6 (or newer) automatically find the appropriate driver.
       // If you use Java> 5, then this line is not needed.
       Class.forName("com.mysql.jdbc.Driver");

       String connectionURL = "jdbc:mysql://" + hostName + ":3306/" + dbName;

       Connection conn = DriverManager.getConnection(connectionURL, userName,
               password);
       return conn;
   }
}
SQLServerConnUtils_JTDS.java
package org.o7planning.tutorial.jdbc;

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

public class SQLServerConnUtils_JTDS {


   // Connect to SQLServer
   // (Using JDBC Driver of JTDS library)
   public static Connection getSQLServerConnection()
           throws SQLException, ClassNotFoundException {
       String hostName = "localhost";
       String sqlInstanceName = "SQLEXPRESS";
       String database = "simplehr";
       String userName = "sa";
       String password = "1234";

       return getSQLServerConnection(hostName, sqlInstanceName, database,
               userName, password);
   }

   // Connect to SQLServer & using JTDS library
   public static Connection getSQLServerConnection(String hostName,
           String sqlInstanceName, String database, String userName,
           String password) throws ClassNotFoundException, SQLException {

       // Declare the class Driver for SQLServer DB
       // This is necessary with Java 5 (or older)
       // Java6 (or newer) automatically find the appropriate driver.
       // If you use Java> 5, then this line is not needed.        
       Class.forName("net.sourceforge.jtds.jdbc.Driver");

       // Example:
       // jdbc:jtds:sqlserver://localhost:1433/simplehr;instance=SQLEXPRESS
       String connectionURL = "jdbc:jtds:sqlserver://" + hostName + ":1433/"
               + database + ";instance=" + sqlInstanceName;

       Connection conn = DriverManager.getConnection(connectionURL, userName,
               password);
       return conn;
   }

}
SQLServerConnUtils_SQLJDBC.java
package org.o7planning.tutorial.jdbc;

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

public class SQLServerConnUtils_SQLJDBC {

   // Connect to SQLServer
   // (Using JDBC Driver: SQLJDBC)
   public static Connection getSQLServerConnection()
           throws SQLException, ClassNotFoundException {
       String hostName = "localhost";
       String sqlInstanceName = "SQLEXPRESS";
       String database = "simplehr";
       String userName = "sa";
       String password = "1234";

       return getSQLServerConnection(hostName, sqlInstanceName,
               database, userName, password);
   }

   //
   // Connect to SQLServer & using SQLJDBC Library.
   public static Connection getSQLServerConnection(String hostName,
           String sqlInstanceName, String database, String userName,
           String password) throws ClassNotFoundException, SQLException {
       
       // Declare the class Driver for SQLServer DB
       // This is necessary with Java 5 (or older)
       // Java6 (or newer) automatically find the appropriate driver.
       // If you use Java> 5, then this line is not needed.        
       Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");


       // jdbc:sqlserver://ServerIp:1433/SQLEXPRESS;databaseName=simplehr
       String connectionURL = "jdbc:sqlserver://" + hostName + ":1433"
               + ";instance=" + sqlInstanceName + ";databaseName=" + database;

       Connection conn = DriverManager.getConnection(connectionURL, userName,
               password);
       return conn;
   }

}
ODBCConnUtils.java
package org.o7planning.tutorial.jdbc;

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

public class ODBCConnUtils {

    // Connect to ODBC Data Source named "simplehr-ds".
    public static Connection getJdbcOdbcConnection() throws SQLException,
            ClassNotFoundException {
        String odbcDataSourceName = "simplehr-ds";
        String userName = "simplehr";
        String password = "simplehr";
        return getJdbcOdbcConnection(odbcDataSourceName, userName, password);
    }

    public static Connection getJdbcOdbcConnection(String odbcDataSourceName,
            String userName, String password) throws SQLException,
            ClassNotFoundException {
 
        // Declare the class Driver for JDBC-ODBC Bridge
        // This is necessary with Java 5 (or older)
        // Java6 (or newer) automatically find the appropriate driver.
        // If you use Java> 5, then this line is not needed.        
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

        String connectionURL = "jdbc:odbc:" + odbcDataSourceName;

        Connection conn = DriverManager.getConnection(connectionURL, userName,
                password);
        return conn;
    }
}
You can change  ConnectionUtils class for connecting to familiar Database, and run this class for testing the connection.

Note: If you use MySQL or SQL Server by default two Database prevent connecting to it from other IP address. You need to configure it so that this connection is allowed. You can see the instruction in the installing and configuration document of MySQL, SQL Server on the o7planning.

Installing and Configuring MySQL Community:

Installing and Configuring SQL Server:

7- Using the JDBC API to query data

This is a data in Employee table. We see how Java query data through an example:
ResultSet is a Java object returned when you query data. Using  ResultSet.next() for moving the cursor to the next records (Move by row). In a particular record, you use  ResultSet.getXxx() methods for getting values in columns. Columns are arranged in ordinal number (1, 2, 3...).
  • Interface ResultSet
public String getString(int columnIndex) throws SQLException;
public boolean getBoolean(int columnIndex) throws SQLException;
public int getInt(int columnIndex) throws SQLException;
public double getDouble(int columnIndex) throws SQLException;

...

public String getString(String columnLabel) throws SQLException;
public boolean getBoolean(String columnLabel) throws SQLException;
public int getInt(String columnLabel) throws SQLException;
public double getDouble(String columnLabel) throws SQLException;

....
Example:
QueryDataExample.java
package org.o7planning.tutorial.jdbc.basic;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class QueryDataExample {

    public static void main(String[] args) throws ClassNotFoundException,
            SQLException {

        // Get Connection
        Connection connection = ConnectionUtils.getMyConnection();

        // Create statement
        Statement statement = connection.createStatement();

        String sql = "Select Emp_Id, Emp_No, Emp_Name from Employee";

        // Execute SQL statement returns a ResultSet object.
        ResultSet rs = statement.executeQuery(sql);

        // Fetch on the ResultSet        
        // Move the cursor to the next record.
        while (rs.next()) {
            int empId = rs.getInt(1);
            String empNo = rs.getString(2);
            String empName = rs.getString("Emp_Name");
            System.out.println("--------------------");
            System.out.println("EmpId:" + empId);
            System.out.println("EmpNo:" + empNo);
            System.out.println("EmpName:" + empName);
        }

        // Close connection.
        connection.close();
    }

}
Results of running the example:

8- ResultSet types

You have got accustomed with  ResultSet through above examples. By default, when fetch data, The cursor only can move from top to bottom and from right to left. It means that with default  ResultSet you can't call:
  • ResultSet.previous()  : step back a record.
  • On the same record, you can't call ResultSet.getXxx(4) first, and then call ResultSet.getXxx(2).
An intentional call causes to an Exception.
public  Statement createStatement(int resultSetType, int resultSetConcurrency)
       throws SQLException;

// Example:
Statement statement = connection.createStatement(
               ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);

// ResultSet can scroll & readonly
ResultSet rs = statement.executeQuery(sql);
resultSetType Meaning
TYPE_FORWARD_ONLY - The constant indicating the type for a ResultSet object whose cursor may move only forward.
TYPE_SCROLL_INSENSITIVE - The constant indicating the type for a ResultSet object that is scrollable but generally not sensitive to changes to the data that underlies the ResultSet.
TYPE_SCROLL_SENSITIVE - The constant indicating the type for a ResultSet object that is scrollable and generally sensitive to changes to the data that underlies the ResultSet.
 
resultSetConcurrency Meaning
CONCUR_READ_ONLY - The constant indicating the concurrency mode for a ResultSet object that may NOT be updated.
CONCUR_UPDATABLE - The constant indicating the concurrency mode for a ResultSet object that may be updated.
ScrollableResultSetExample.java
package org.o7planning.tutorial.jdbc.basic;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class ScrollableResultSetExample {

    public static void main(String[] args) throws ClassNotFoundException,
            SQLException {

        // Get a Connection
        Connection connection = ConnectionUtils.getMyConnection();


        // Create a Statement object
        // can be srolled, but not sensitive to changes under DB.
        // ResultSet is readonly (Cannot update)
        Statement statement = connection.createStatement(
                ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);

        String sql = "Select Emp_Id, Emp_No, Emp_Name from Employee";


        // Execute statement, return ResultSet.
        ResultSet rs = statement.executeQuery(sql);

        
        // Jump the cursor to last record.
        boolean last = rs.last();
        
        System.out.println("last : "+ last);
        
        
        if(last) {
            // Print out data of last record
            System.out.println("EmpId:" + rs.getInt(1));
            System.out.println("EmpNo:" + rs.getString(2));
            System.out.println("EmpName:" + rs.getString(3));
        }
        
        
        System.out.println("--------------------");
        
        // Move cursor to previous record
        boolean previous =rs.previous();
        System.out.println("Previous 1: "+ previous);
        
        // Move cursor to previous record
        previous =rs.previous();
        System.out.println("Previous 2: "+ previous);       
        
        // Fetch in the ResultSet
        while (rs.next()) {
            // Get value of column 2
            String empNo = rs.getString(2);

            // Then get the value of column 1.
            int empId = rs.getInt(1);
            
            String empName = rs.getString("Emp_Name");
            
            System.out.println("--------------------");
            System.out.println("EmpId:" + empId);
            System.out.println("EmpNo:" + empNo);
            System.out.println("EmpName:" + empName);
        }

        // Close connection.
        connection.close();
    }

}
Results of running the example:

9- Insert example

InsertDataExample.java
package org.o7planning.tutorial.jdbc.basic;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class InsertDataExample {

    public static void main(String[] args) throws ClassNotFoundException,
            SQLException {

        // Get Connection
        Connection connection = ConnectionUtils.getMyConnection();

        Statement statement = connection.createStatement();

        String sql = "Insert into Salary_Grade (Grade, High_Salary, Low_Salary) "
                + " values (2, 20000, 10000) ";
        
        // Execute statement
        // executeUpdate(String) using for Insert, Update, Delete statement.
        int rowCount = statement.executeUpdate(sql);
            
        System.out.println("Row Count affected = " + rowCount);
    }
}
Results of running the example:

10- PreparedStatement

PreparedStatement is an extends Interface of  Statement.
PreparedStatement is used for preparing SQL statement, reusing many times, and helping speed up the program.
PrepareStatementExample.java
package org.o7planning.tutorial.jdbc.pareparedstatement;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class PrepareStatementExample {

    public static void main(String[] args) throws ClassNotFoundException,
            SQLException {

        // Get a connection
        Connection connection = ConnectionUtils.getMyConnection();

        // Create a SQL statement with two parameters (?)
        String sql = "Select emp.Emp_Id, emp.Emp_No, emp.Emp_Name,"
                + " emp.Dept_Id from Employee emp "
                + " where emp.Emp_Name like ? and emp.Dept_Id = ? ";

        // Create a PreparedStatement object.
        PreparedStatement pstm = connection.prepareStatement(sql);

        // Set value for the first parameter (First '?')
        pstm.setString(1, "%S");

        // Set value for the second parameter (Second '?')
        pstm.setInt(2, 20);

        ResultSet rs = pstm.executeQuery();

        while (rs.next()) {
            System.out.println(" ---- ");
            System.out.println("EmpId : " + rs.getInt("Emp_Id"));
            System.out.println("EmpNo : " + rs.getString(2));
            System.out.println("EmpName : " + rs.getString("Emp_Name"));
        }
        
        System.out.println();
        System.out.println("Set other parameters ..");

        // Reuse PreparedStatement
        // Set other values
        pstm.setString(1, "KI%");
        pstm.setInt(2,10);
        
        // Execute statement.
        rs = pstm.executeQuery();
        
        while (rs.next()) {
            System.out.println(" ---- ");
            System.out.println("EmpId : " + rs.getInt("Emp_Id"));
            System.out.println("EmpNo : " + rs.getString(2));
            System.out.println("EmpName : " + rs.getString("Emp_Name"));
        }
    }
}
Results of running the example:

11- CallableStatement

CallableStatement used to call a stored procedure or SQL functions.
// Statement call procedure from Java
String sql = "{call procedure_name(?,?,?)}";

// Statement call function from Java.
String sql ="{? = call function_name(?,?,?)}";
For example with CallableStatement we need a function or a procedure in DB. With Oracle, MySQL or SQLServer you can quickly create a procedure as below:
  • ORACLE
-- This procedure retrieves information of an employee,
-- Input parameter: p_Emp_ID (Integer)
-- There are four output parameters v_Emp_No, v_First_Name, v_Last_Name, v_Hire_Date

Create Or Replace Procedure Get_Employee_Info(p_Emp_Id     Integer
                                           ,v_Emp_No     Out Varchar2
                                           ,v_First_Name Out Varchar2
                                           ,v_Last_Name  Out Varchar2
                                           ,v_Hire_Date  Out Date) Is
Begin
 v_Emp_No := 'E' || p_Emp_Id;
 --
 v_First_Name := 'Michael';
 v_Last_Name  := 'Smith';
 v_Hire_Date  := Sysdate;
End Get_Employee_Info;
  • MySQL
-- This procedure retrieves information of an employee,
-- Input parameter: p_Emp_ID (Integer)
-- There are four output parameters v_Emp_No, v_First_Name, v_Last_Name, v_Hire_Date

CREATE PROCEDURE get_Employee_Info(p_Emp_ID     Integer,
                                   out       v_Emp_No        Varchar(50) ,
                                   out       v_First_Name    Varchar(50) ,
                                   Out       v_Last_name    Varchar(50) ,
                                   Out       v_Hire_date      Date)
BEGIN
 set v_Emp_No  = concat( 'E' , Cast(p_Emp_Id as char(15)) );
--
 set v_First_Name = 'Michael';
 set v_Last_Name  = 'Smith';
 set v_Hire_date  = curdate();
END
  • SQLServer
-- This procedure retrieves information of an employee,
-- Input parameter: p_Emp_ID (Integer)
-- There are four output parameters v_Emp_No, v_First_Name, v_Last_Name, v_Hire_Date

CREATE PROCEDURE Get_Employee_Info
     @p_Emp_Id       Integer ,
     @v_Emp_No      Varchar(50)   OUTPUT,
     @v_First_Name  Varchar(50)   OUTPUT,
     @v_Last_Name  Varchar(50)   OUTPUT,
     @v_Hire_Date    Date             OUTPUT
AS
BEGIN
     set @v_Emp_No  =   'E' + CAST( @p_Emp_Id as varchar)  ;
     --
     set @v_First_Name = 'Michael';
     set @v_Last_Name  = 'Smith';
     set @v_Hire_date  = getdate();
END
CallableStatementExample.java
package org.o7planning.tutorial.jdbc.callablestatement;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.Date;
import java.sql.SQLException;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class CallableStatementExample {

    public static void main(String[] args) throws ClassNotFoundException,
            SQLException {

        // Get a connection
        Connection connection = ConnectionUtils.getMyConnection();


        String sql = "{call get_Employee_Info(?,?,?,?,?)}";

        // Create a CallableStatement object.
        CallableStatement cstm = connection.prepareCall(sql);

       
        // Set parameter value for first question mark
        // (p_Emp_ID)
        cstm.setInt(1, 10);

       
        // Registers the OUT parameter for 2st question mark.
        // (v_Emp_No)
        cstm.registerOutParameter(2, java.sql.Types.VARCHAR);        
       
        // Registers the OUT parameter for 3rd question mark.
        // (v_First_Name)        
        cstm.registerOutParameter(3, java.sql.Types.VARCHAR);

        // Registers the OUT parameter for 4th question mark.
        // (v_Last_Name)        
        cstm.registerOutParameter(4, java.sql.Types.VARCHAR);


        // Registers the OUT parameter for 5th question mark.
        // (v_Hire_Date)        
        cstm.registerOutParameter(5, java.sql.Types.DATE);

        // Execute statement.
        cstm.executeUpdate();

        String empNo = cstm.getString(2);
        String firstName = cstm.getString(3);
        String lastName = cstm.getString(4);
        Date hireDate = cstm.getDate(5);

        System.out.println("Emp No: " + empNo);
        System.out.println("First Name: " + firstName);
        System.out.println("Last Name: " + lastName);
        System.out.println("Hire Date: " + hireDate);

    }
}
Results of running the example:

12- Control Transaction

Transaction is an important concept in SQL.

For example, A person send a sum of 1,000 dollar to B person's account, so there are two actions happening in Database:

    Debit 1,000 dollar on the A person's account
    Credit 1,000 dollar on the B person's account.

And the transaction is considered successful if two above steps are implemented successfully. On the contrary, if one of two steps is fails, the transaction should be considered unsuccessfully and we will have to have a rollback from the early status.
TransactionExample.java
package org.o7planning.tutorial.transaction;

import java.sql.Connection;
import java.sql.SQLException;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class TransactionExample {

    private static void doJob1(Connection conn) {
        // Todo something here.
    }

    private static void doJob2(Connection conn) {
        // Todo something here.
    }

    public static void main(String[] args) throws ClassNotFoundException,
            SQLException {

        // Get a connection
        Connection connection = ConnectionUtils.getMyConnection();
           
        // Set auto-commit to false
        connection.setAutoCommit(false);

        try {
 
            // Do something related to the DB.
            doJob1(connection);
 
            doJob2(connection);
 
            // Explicitly commit statements to apply changes
            connection.commit();

        }
 
        // Handling exception
        catch (Exception e) {
            e.printStackTrace();
 
            // Rollback changes
            connection.rollback();
        }
 
        // Close connection.
        connection.close();
    }

}

13- Execute a batch command

BatchExample.java
package org.o7planning.tutorial.transaction;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class BatchExample {

    public static void main(String[] args) throws SQLException,
            ClassNotFoundException {

        Connection conn = ConnectionUtils.getMyConnection();

        try {
            // Create statement object
            Statement stmt = conn.createStatement();

            // Set auto-commit to false
            conn.setAutoCommit(false);

            // Create SQL statement to insert into Employee table.
            String sql1 = "Update Employee emp set emp.Salary = emp.Salary + 100 "
                    + " where emp.Dept_Id = 10 ";
            
            // Add above SQL statement in the batch.
            stmt.addBatch(sql1);

            // Create one more SQL statement
            String sql2 = "Update Employee emp set emp.Salary = emp.Salary + 20 "
                    + " where emp.Dept_Id = 20 ";
            
            // Add above SQL statement in the batch.
            stmt.addBatch(sql2);

            // Create one more SQL statement
            String sql3 = "Update Employee emp set emp.Salary = emp.Salary + 30 "
                    + " where emp.Dept_Id = 30 ";
            
            // Add above SQL statement in the batch.
            stmt.addBatch(sql3);

            // Create an int[] to hold returned values
            int[] counts = stmt.executeBatch();

            System.out.println("Sql1 count = " + counts[0]);
            System.out.println("Sql2 count = " + counts[1]);
            System.out.println("Sql3 count = " + counts[2]);

            // Explicitly commit statements to apply changes
              conn.commit();
        } catch (Exception e) {
            e.printStackTrace();
            conn.rollback();
        }
    }

}
Results of running the example:
BatchExample2.java
package org.o7planning.tutorial.transaction;

import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.UUID;

import org.o7planning.tutorial.jdbc.ConnectionUtils;

public class BatchExample2 {

    public static void main(String[] args) throws ClassNotFoundException,
            SQLException {

        Connection conn = ConnectionUtils.getMyConnection();

        try {
            String sql = "Insert into Timekeeper(Timekeeper_Id, Date_Time, In_Out, Emp_Id) "
                    + " values (?,?,?,?) ";
            // Create statement object
            PreparedStatement stmt = conn.prepareStatement(sql);

            // Set auto-commit to false
            conn.setAutoCommit(false);

            // Set values for parameters
            stmt.setString(1, UUID.randomUUID().toString());
            stmt.setDate(2, new Date(System.currentTimeMillis()));
            stmt.setString(3, "I");
            stmt.setInt(4, 7839);
            
            // Add to batch
            stmt.addBatch();


            // Set other values for parameters.
            stmt.setString(1, UUID.randomUUID().toString());
            stmt.setDate(2, new Date(System.currentTimeMillis()));
            stmt.setString(3, "I");
            stmt.setInt(4, 7566);

            // Add to batch.
            stmt.addBatch();
        

            // Create an int[] to hold returned values
            int[] counts = stmt.executeBatch();

            System.out.println("counts[0] = " + counts[0]);
            System.out.println("counts[1] = " + counts[1]);

            // Explicitly commit statements to apply changes
            conn.commit();
        } catch (Exception e) {
            e.printStackTrace();
            conn.rollback();
        }
    }

}
Results of running the example: