APJII lab 01

- Adding JDBC Driver Type 4 file sqljdbc4.jar library to your class path - Loading Driver try { Class.forName”com.microsoft.sqlserver.jdbc.SQLServerDriver”; //Or any other driver } catch

LAB GUIDE – SEMESTER 2 – ACCP I.10

COURSE: APJ II

LAB: 01

APJ II Lab 1

Objectives:

In this session, you will be practicing with:

 JDBC driver type IV

 JDBC application development process

 Statement class

 PreparedStatement class

 ResultSet interface

 ResultSetMetaData

Part I: Workshop – 15 minutes

1 Students open workshop in CD ROM, then View, Run, Think about it (10 minutes)

Part II: Step by step – 45 minutes

Guide 01: Step to connect to MSSQL Server 2005/2008 using JDBC Driver Type 4:

- Create Application Project in Netbeans

- Adding JDBC Driver Type 4 (file sqljdbc4.jar) library to your class path

- Loading Driver

try {

Class.forName(”com.microsoft.sqlserver.jdbc.SQLServerDriver”); //Or any other driver

}

catch(Exception x){

System.out.println( “Unable to load the driver class!” );

}

- Create JDBC Connection: Using getConnection( ) of DriverManager for getting connection to

database It uses username, password, and JDBC url

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

String url = "jdbc:sqlserver://localhost:1433;databaseName=c1108g";

String username="sa";

String password= "12345678";

Connection connection = DriverManager.getConnection(url, username, password);

System.out.println("Connected: " + connection);

- Create Statement Object

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

In these practices, you will use Statement, or PreparedStatement

Statement st = connection.createStatement();

PreparedStatement prst = conn.prepareStatement(sql);

Statement methods:

- Executing a SELECT statement with the Statement object, and returning a JDBC ResultSet

String query = "select * from persons";

ResultSet rs = st.executeQuery(query);//using for select

//Moi lan rs.next() thi se chuyen sang dong tiep theo

while(rs.next()){

String name = rs.getString(2);

System.out.println("Name: " + name);

}

- Executing a modify statement with the Statement object, and returning number of modified values String query = "INSERT INTO PERSONS VALUES('Phuong')";

int i = st.executeUpdate(query);//executeUpdate using for Insert, update, delete

if(i> 0){

System.out.println("Inserted");

}else{

System.out.println("No row affected");

}

Example 01: Following codes show how to establish connection to database and using Statement

object to retrieve data and modify data:

1 Run script below to create database and table in MSSQL Server 2005/2008:

create database c1108g

go

use c1108g

go

create table Persons(

id int primary key identity(1,1), name varchar(90)

select t.*, CONVERT(varchar,getdate(),103) current_day from persons t

insert into Persons values('Luong');

insert into Persons values('Luong1');

insert into Persons values('Luong2');

2 Create class named Connector: in this example, you use Statement without parameterized

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public class Connector {

public static void main(String[] args) throws Exception{

try{

//Tao ket noi database

//Buoc 01: Register Driver Approach 01

//com.microsoft.sqlserver.jdbc.SQLServerDriver

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance();

//Approach 02 for reistering driver:

//DriverManager.registerDriver(new com.microsoft.sqlserver.jdbc.SQLServerDriver());

//Buoc 02: tao ket noi

String url = "jdbc:sqlserver://localhost:1433;databaseName=c1108g";

String username="sa";

String password= "12345678";

Connection connection = DriverManager.getConnection(url, username, password);

//Co the gap mot so loi: khong ket noi duoc cong, sai URL, sai username, password

System.out.println("Connected: " + connection);

//Buoc 03: Thuc thi cac cau lenh

//Buoc 03.01: Tao ra statement

Statement st = connection.createStatement();

//Buoc 03.02 (optiinal): select table, return resultset

String query = "select * from persons";

ResultSet rs = st.executeQuery(query);//using for select

//Moi lan rs.next() thi se chuyen sang dong tiep theo

while(rs.next()){

String name = rs.getString(2);

System.out.println("Name: " + name);

}

//Buoc 03.03: Cac cau lenh update neu co

query = "INSERT INTO PERSONS VALUES('Phuong')";

int i = st.executeUpdate(query);//executeUpdate using for Insert, update, delete

if(i> 0){

System.out.println("Inserted");

}else{

System.out.println("No row affected");

}

//Close Resources

rs.close();

st.close();

connection.close();

}catch(SQLException e){

e.printStackTrace();

}

}

}

3

2 Class named PreparedStatementDemo: using statement object with parameterized

(PreparedStatement)

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

public class PreparedStatementDemo {

public static void main(String[] args) throws Exception {

//Tao ket noi database

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance();

String url = "jdbc:sqlserver://localhost:1433;databaseName=C1108G";

Connection conn = DriverManager.getConnection(url, "sa", "12345678");

String sql = "select * from persons where name like ?";

PreparedStatement prst = conn.prepareStatement(sql);

//Cai dat tham so

prst.setString(1, "PHuong");

ResultSet rs = prst.executeQuery();

while (rs.next()) {

System.out.println(rs.getString(2));

}

//Insert, Update, delete

sql = "update persons set name = ? where id=?";

prst = conn.prepareStatement(sql);

prst.setString(1, "Trung XYZQ");

prst.setInt(2, 5);

prst.executeUpdate();

rs.close();

prst.close();

conn.close();

}

}

Guide 02: Using ResultSetMetaData:

ResultSetMetaData Interface holds information on the types and properties of the columns in a

ResultSet It is constructed from the Connection object

Example 02: Using ResultSetMetaData

import java.sql.Connection;

import java.sql.DatabaseMetaData;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

public class DatabaseMetaInfo {

public static void main(String[] args) throws Exception{

//Tao ket noi database

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance();

String url = "jdbc:sqlserver://localhost:1433;databaseName=C1108G";

Connection conn = DriverManager.getConnection(url, "sa", "12345678");

//Get Database Metadata

DatabaseMetaData metaData = conn.getMetaData();

String databaseProductName = metaData.getDatabaseProductName();

String databaseProductVersion = metaData.getDatabaseProductVersion();

System.out.printf("Name: %s Version: %s\n", databaseProductName,databaseProductVersion); PreparedStatement prst = conn.prepareStatement("select t01.*,getdate() as current_day from persons t01");

//get result meta data

ResultSet rs = prst.executeQuery();

ResultSetMetaData rsMeta = rs.getMetaData();

for(int i = 1; i<= rsMeta.getColumnCount(); i++){

String columnName = rsMeta.getColumnName(i);

System.out.println("COLUMN NAME: " + columnName);

}

//Close Resource

rs.close();

conn.close();

}

}

Part III: Do it yourself – 60 minutes

Exercise 1: By extending from two examples above, you write 2 programs as below:

When user clicked on Add, program automatically add new record to database, and display it to the JTable

Building program shown in next figure:

Exercise 2: Write a Java application StudentDetails that will add, modify and delete records from a student table The student table has the structure as shown in this table:

Column Name

Data Type

Rollno Numeric Class Varchar The output of the program is as shown as below.

Part IV: Homework

Exercise 1: Do assignment of module 1 in CD ROM

References

1) CD ROM APJ II, Aptech Education

2) http://docs.oracle.com/javase/tutorial/jdbc/basics/