java连接jdbc代码,java连接数据库jdbc

java连接数据库的代码

用这个类吧.好的话,给我加加分.

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import java.sql.*;

/**

* @功能: 一个JDBC的本地化API连接类,封装了数据操作方法,只用传一个SQL语句即可

* @作者: 李开欢

* @日期: 2007/

*/

public class ConnectionDemo {

/*

* 这里可以将常量全部放入另一个类中,以方便修改

*/

private static Connection conn;

private static Statement ps;

private static ResultSet rs;

private static final String DRIVER = "com.microsoft.jdbc.sqlserver.SQLServerDriver";

private static final String URL = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=mydb";

private static final String USER ="sa";

private static final String PASS = "sa";

public ConnectionDemo() {

// TODO Auto-generated constructor stub

ConnectionDemo.getConnection();

}

public static Connection getConnection(){

System.out.println("连接中...");

try {

Class.forName(ConnectionDemo.DRIVER);

conn = DriverManager.getConnection(ConnectionDemo.URL, ConnectionDemo.USER, ConnectionDemo.PASS);

System.out.println("成功连接");

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return conn;

}

public static Statement getStatement(String sql){

System.out.println("执行SQL语句中...");

try {

ps = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);

if(sql.substring(0, 6).equals("select")){

rs = ps.executeQuery(sql);

System.out.println("执行完查询操作,结果已返回ResultSet集合");

}else if(sql.substring(0, 6).equals("delete")){

ps.executeUpdate(sql);

System.out.println("已执行完毕删除操作");

}else if(sql.substring(0, 6).equals("insert")){

ps.executeUpdate(sql);

System.out.println("已执行完毕增加操作");

}else{

ps.executeUpdate(sql);

System.out.println("已执行完毕更新操作");

}

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return ps;

}

public static ResultSet getResultSet(){

System.out.println("查询结果为:");

return rs;

}

public static void closeConnection(){

System.out.println("关闭连接中...");

try {

if (rs != null) {

rs.close();

System.out.println("已关闭ResultSet");

}

if (ps != null) {

ps.close();

System.out.println("已关闭Statement");

}

if (conn != null) {

conn.close();

System.out.println("已关闭Connection");

}

} catch (Exception e) {

// TODO: handle exception

}

}

public static void main(String[] args) {

// TODO Auto-generated method stub

ConnectionDemo.getConnection();

String sql = "delete from type where id = 1";

ConnectionDemo.getStatement(sql);

String sql2 = "insert into type values(1,'教学设备')";

ConnectionDemo.getStatement(sql2);

String sql1 = "select * from type";

ConnectionDemo.getStatement(sql1);

ResultSet rs = ConnectionDemo.getResultSet();

System.out.println("编号 "+"类 型");

try {

while(rs.next()){

System.out.print(" "+rs.getInt(1)+" ");

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

}

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

ConnectionDemo.closeConnection();

}

}

利用java代码,编写JDBC连接数据库新增员工信息的步骤. 员工信息表:t_emp(id int？

第一步：新建数据库

连接的是本地localhost，新建一个新的数据库名是jdbctest

然后建表t_emp

不会的话可通过执行下方的sql语句建表

CREATE TABLE `t_emp` (

`id` int(11) NOT NULL AUTO_INCREMENT,

`name` varchar(255) DEFAULT NULL,

`salary` double DEFAULT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

第二步：新建java项目

新建完以后添加mysql驱动的jar包，jar包自己下载

在项目上右键鼠标属性，然后

添加jar包，我这里已经加载过了

第三步：编写代码

package com.gf;

import java.sql.DriverManager;

import java.sql.SQLException;

import com.mysql.jdbc.Connection;

import com.mysql.jdbc.Statement;

public class Test {

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

int flag=0;

//1.加载驱动

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

//2.获取连接

Connection conn=(Connection) DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbctest?user=rootpassword=123456useUnicode=truecharacterEncoding=UTF-8");

//3.创建statement

Statement sm=(Statement) conn.createStatement();

//4.执行sql语句

flag=sm.executeUpdate("insert into t_emp(name,salary) values('菲菲',34.9)");

if(flag!=0) {

System.out.println("员工信息增加成功");

}else {

System.out.println("添加失败");

}

}

}

注意点：

---------------------------------------------------------------------------------

DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbctest?user=rootpassword=123456useUnicode=truecharacterEncoding=UTF-8");

这里需要修改自己本机的连接信息，不然会出现连接失败

最后的执行结果

java 实现 jdbc连接oracle 数据库的java代码怎么写

package com.jdbc.test;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

public class JDBCTest {

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

//1.加载驱动

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

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

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

//2.创建数据库连接对象

//Connection conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;databaseName=db","sa","sqlpass");

//Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/db?useUnicode=truecharacterEncoding=UTF-8","root","123456");

Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","scott","Oracle123");

//3.创建数据库命令执行对象

Statement stmt = conn.createStatement();

// PreparedStatement ps = conn.prepareStatement("select * from t_user");

//4.执行数据库命令

ResultSet rs = stmt.executeQuery("select * from t_user");

// ResultSet rs = ps.executeQuery();

//5.处理执行结果

while (rs.next()) {

int id = rs.getInt("id");

String username = rs.getString("username");

String password = rs.getString("password");

System.out.println(id + "\t" + username + "\t" + password);

}

//6.释放数据库资源

if (rs != null) {

rs.close();

}

// if (ps != null) {

// ps.close();

// }

if (stmt != null) {

stmt.close();

}

if (conn != null) {

conn.close();

}

}

}

这是以前写的3中数据库的链接已经测试过了。