java db数据库,JAVADB数据库实例
JAVADB数据库范例
关于javaDB的介绍就不说了，直接上例子。
首先将derby.jar添加到classpath下面(IDE的话直接引入)
import java.sql.*;
import java.util.*;
import java.io.*;
public class Test
{
public static void main(String[] args) throws Exception{
DBHelper db = new DBHelper();
db.createUserTable();
db.insertUser(1,"zhangsan2","123");
db.insertUser(1,"zhangsan3","1233");
db.insertUser(1,"zhangsan4","1234");
db.insertUser(1,"zhangsan5","12345");
ResultSet rs = db.query();
while(rs.next()){
int id = rs.getInt("id");
String name = rs.getString("name");
String pwd = rs.getString("password");
System.out.println("id->" + id + "\tname->" + name + "\tpassword->" + pwd);
}
rs.close();
}
}
/**
* 数据库工具类
*/
class DBHelper
{
private Connection con = null ; //连接
public DBHelper(){
//loadDriver("org.apache.derby.jdbc.EmbeddedDriver"); //load driver jdk6可以省略加载驱动这一步
getConnection(); //init Connection
}
//load driver class
private void loadDriver(String driveName){
try{
Class.forName(driveName);
}catch(Exception e){
e.printStackTrace();
System.out.println("load driver failure");
}
}
//get Connection
private void getConnection(){
try{
//con = DriverManager.getConnection("jdbc:derby:userDB;create=true;user=test;password=test");//userDB创建在class运行目录
//con = DriverManager.getConnection("jdbc:derby:a/b/userDB;create=true;user=test;password=test");//userDB创建在class下面的a/b文件夹下面，
con = DriverManager.getConnection("jdbc:derby:d:/a/b/userDB;create=true;user=test;password=test");//userDB创建在d盘下面的a/b文件夹下面，
}catch(Exception e){
e.printStackTrace();
}
}
//create simple table for test
public void createUserTable(){
try{
Statement stat = con.createStatement();
String sql_create = "create table tb_user(id int,name varchar(20),password varchar(20))";
stat.execute(sql_create);
stat.close();
}catch(Exception e){
e.printStackTrace();
}
}
//insert user info
public void insertUser(int id,String name,String pwd){
String sql_insert = "insert into tb_user values (?,?,?)";
try{
PreparedStatement pst = con.prepareStatement(sql_insert);
pst.setInt(1,id);
pst.setString(2,name);
pst.setString(3,pwd);
int i = pst.executeUpdate();
}catch(Exception e){
e.printStackTrace();
}
}
//query user info
public ResultSet query(){
String sql_insert = "select * from tb_user";
try{
PreparedStatement pst = con.prepareStatement(sql_insert);
return pst.executeQuery();
}catch(Exception e){
e.printStackTrace();
}
return null;
}
}
result:
---------- 直接运行 ----------
id->1 name->zhangsan2 password->123
id->1 name->zhangsan3 password->1233
id->1 name->zhangsan4 password->1234
id->1 name->zhangsan5 password->12345
Output completed (7 sec consumed) - Normal Termination