java 创建连接oracle 数据库并查询数据

package com;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public class Text {

//增加驱动

public static void main(String[] args) {

//2.注册驱动

try {

Class.forName("oracle.jdbc.driver.OracleDriver");

//3.建立连接

String str = "jdbc:oracle:thin:@192.168.31.21:1521:orcl";

Connection con = DriverManager.getConnection(str, "scott", "tiger");

System.out.println("*************正在连接数据库***********");

//4.创建语句

Statement stmt = con.createStatement();

//5.执行语句

ResultSet rs = stmt.executeQuery("select empno,SAL,COMM*2 from emp ");

//6.处理结果

System.out.println("*************已连接连接数据库*********");

System.out.println("*************数据库查询结果**********");

while(rs.next())

{

int i = rs.getInt(1);

int a = rs.getInt(2);

int b = rs.getInt(3);

if(rs.wasNull())

{

System.out.println(i+"\t"+a+"\t"+"无");

}

else

{

String query2 = "update emp set comm=comm*2 where empno="+i;

Statement stmtt = con.createStatement();

stmtt.executeUpdate(query2);

System.out.println(i+"\t"+a+"\t"+b);

}

}

//7.释放资源

rs.close();

stmt.close();

con.close();

} catch (ClassNotFoundException e) {

e.printStackTrace();

} catch (SQLException e) {

if(e.getErrorCode()==1017)//getErrorCode检索此 SQLException 对象的特定于供应商的异常代码

System.out.println("用户名或密码错误");

else

{

System.out.println(e.getMessage());//getMessage 方法用来获取异常的信息

}

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}