Java C8. JDBC ppt

Editing Database with DBEditDatabase structure Database data Attribute properties... Connection to database Connection java.sql.DriverManager.getConnectionString urlDatabase, String u

Chapter 8 JDBC

ITSS Java Programming NGUYEN Hong Quang, HUT

Components of JDBC

JDBC 1

 JDBC API

 ‘java.sql’ and ‘javax.sql’ package

 SQL Interfaces for application

 JDBC Driver Manager

 manage two or more JDBC drivers

 ‘DriverManager’ class in the java.sql package

 Native API partly – Java technology-based driver

 Net-protocol all - Java technology-based driver

 Native-protocol Java technology-based driver

Setting classpath for JDBC

DbEdit plug-ins : install

Activate DbEdit

Connecting DbEdit with MySQL

Editing Database with DBEdit

Database

structure

Database data

Attribute properties

Execute SQL command with DbEdit

 Resultset.getParameter

 Connection.close()

Loading of JDBC driver : Exemple

 Exemple : Loading JDBC driver of MySQL database

try {

Class.forName ("com.mysql.jdbc.Driver");

}

catch (ClassNotFoundException e){

System.err.println (“Do not connect");

}

 Note : set CLASSPATH to find JDBC Driver class (slide 5)

Connection to database

 Connection java.sql.DriverManager.getConnection(String urlDatabase, String userName, String password) throws SQLException

 Create a connection to the urlDatabase : return the

Connection to database : Exemple

String userName = “student";

String userPassword = “student";

String url = "jdbc:mysql://localhost:3306/qlsv";

Execution of Select SQL statement

 ResultSet java.sql.Statement.executeQuery(String

sqlStatement) throws SQLException

 Execute Select SQL statement

 Return an ResultSet object

Execution of Select SQL statement : Exemple

Statement stmt = null;

ResultSet res = null;

String sql = "Select * From Student";

Processing data in a ResultSet object

Start rs.next

rs.getInt(“ID”)

rs.getInt(1)

rs.getString(“NAME”)

rs.getString(2)

List of getting data method

CHAR, VARCHAR, LONGVARCHAR String getString

NUMERIC, DECIMAL java.math.Decimal getBigDecimal

BINARY, VARBINARY,

Execution of Select SQL statement : Exemple

String sql = "Select * From Student";

try {

res = stmt.executeQuery(sql);

while (res.next()) {

Integer id = res.getInt("ID");

String name = res.getString("Name");

System out.println(id + " " + name);

ResultSet : exemple

Execution of others SQL statement :

INSERT, UPDATE, DELETE

 Syntax: int java.sql.Statement.executeUpdate(String

sqlStatement) throws SQLException

 Execute SQL statement: INSERT, UPDATE, or DELETE

Exemple Update SQL Statement

String sql = "Update Student Set score=8 Where id=3";

Exemple Update SQL Statement

Application sample : Summary

 Create database “qlsv” and table “student” in

 Calling a Query SQL statement

 Calling a Update SQL statement

 Close connection

Database Administation with MySQL 1

Show databases;

Database Administation with MySQL 2

 Create a database :

CREATE DATABASE TEMPDB;

 Delete that database :

DROP DATABASE TEMPDB;

 Use a database :

USE TEMPDB;

 Display tables in a database :

SHOW TABLES;

Create a table

column_name1 type [modifiers]

[ , column_name2 type [modifiers]] )

CREATE TABLE student (

ID int(6) PRIMARY KEY,

Input records with DbEdit

Show all students : declaration

public class ShowAllStudents {

Connection con = null;

Statement stmt = null;

String userName = "root";

String userPassword = "quangnh";

String drv = "com.mysql.jdbc.Driver";

String url = "jdbc:mysql://localhost:3306/qlsv";

Show all students : connecting to a database

try {

Class.forName (drv);

}

catch (ClassNotFoundException e){

System.err.println ("Do not connect to database");

}

try {

// Connection to database

con = DriverManager.getConnection(url,userName,userPassword); stmt = con.createStatement();

}

catch (SQLException e) {

e.printStackTrace();

}

Show all students : connecting to a database

ResultSet res = null;

String sql = "Select * From Student“;

try {// Execute Select SQL statement

res = stmt.executeQuery(sql);

while (res.next()) {

int id = res.getInt("ID");

String name = res.getString("Name");

int mark = res.getInt("mark");

String address = res.getString("Address");

System.out.println(id + " " + name + " “ + address + " " + mark); }

Close all of object

}

Hands-on exercise

 Install softwares necessary :

 Install MySQL Server

 Install DbEdit plug-ins to Eclipse

 Test Java programs with JDBC :

 Test the ShowAllStudents exemple in the lecture

 Write a Java program to display all of student who has 9 marks

 Update all student who has 7 marks with new 8 marks

 Insert into database the following student :

 “Nguyen Xuan Huy”, “Ha Noi”, “0983567459”, “7”

 Delete all student who live in “Ha Tay”

 DROP TABLE table_name

 Alter table student change score mark int