java连接mysql示例

1、下载连接驱动：mysql-connector-java-5.1.26-bin.jar。

2、导入到项目中，以Eclipse为例：

a、在项目上右键--Build Path--Configure Build Path--Libraries--Add External JARs...---导入下载的连接驱动，结果如图

3、在mysql中创建数据库和表，如下test数据库和admin表，

 

表中数据如下：

  

4、写代码，连接数据库：

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

//数据库连接类
public class DBHelper {
    public static final String url = "jdbc:mysql://localhost/test";
    public static final String name = "com.mysql.jdbc.Driver"; 
    public static final String user = "root"; 
    public static final String password = "root";
    public Connection conn = null;
    public PreparedStatement st = null;
    
    public DBHelper(){
        try {
            Class.forName(name);
            conn = DriverManager.getConnection(url, user, password);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } 
        
    }
    
    public void close(){
        try {
            this.conn.close();
            this.st.close();
        } catch (Exception e) {
            System.out.println("关闭数据链接出错！");
        }
    }
}

测试类：

package dao;

import java.sql.ResultSet;
import java.sql.SQLException;

public class Demo {
    public DBHelper db = new DBHelper();
    public ResultSet rs = null;
    public static void main(String[] args){
        Demo d = new Demo();
//        d.insertAdmin("xl", "xl");
//        d.delectName("xl");
//        d.updateName("xl", "123");
        d.selectAll();
    }
    
    /*
     * 增加记录
     * @name 账号
     * @password 密码
     * @return 成功与否
     * */
    public boolean insertAdmin(String name, String password){
        String sql = "insert into admin(name,password) values(?,?)";
        try {
            db.st = db.conn.prepareStatement(sql);
            db.st.setString(1, name);
            db.st.setString(2, password);
            return db.st.execute();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return false;    
    }
    
    /*
     * 查找所有记录
     * */
    public void selectAll(){
        String sql = "select * from admin";
        try {
            db.st = db.conn.prepareStatement(sql);
            rs = db.st.executeQuery();
            while(rs.next()){
                int id = rs.getInt(1);
                String name = rs.getString(2);
                String password = rs.getString(3);
                System.out.println("id:"+id+" name:"+name+" password:"+password);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    /*
     * 根据账号，删除信息
     * @name 账号
     * @return 成功与否
     * */
    public boolean delectName(String name){
        String sql = "delete from admin where name = ?";
        try {
            db.st = db.conn.prepareStatement(sql);
            db.st.setString(1, name);
            return db.st.execute();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return false; 
    }
    
    
    /*
     * 根据账号，修改密码
     * @name 账号
     * @password 要修改的密码
     * @return 成功与否
     * */
    public int updateName(String name,String password){
        String sql = "update admin set password = ? where name = ?";
        try {
            db.st = db.conn.prepareStatement(sql);
            db.st.setString(1, password);
            db.st.setString(2, name);
            return db.st.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return 0;
    }
}