Java 使用 jdbc 链接 mysql

首先要下载Connector/J地址：http://www.mysql.com/downloads/connector/j/

这是MySQL官方提供的链接方式：

解压后获得jar库文件，须要在工程中导入该库文件

我是用的是Eclipse：

 

 

 JAVA链接MySQL稍微繁琐，因此先写一个类用来打开或关闭数据库：

DBHelper.java

import java.sql.Connection;  
    import java.sql.DriverManager;  
    import java.sql.PreparedStatement;  
    import java.sql.SQLException;  
      
    public class DBHelper {  
        public static final String url = "jdbc:mysql://127.0.0.1/student";  
        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 pst = null;  
      
        public DBHelper(String sql) {  
            try {  
                Class.forName(name);//指定链接类型  
                conn = DriverManager.getConnection(url, user, password);//获取链接  
                pst = conn.prepareStatement(sql);//准备执行语句  
            } catch (Exception e) {  
                e.printStackTrace();  
            }  
        }  
      
        public void close() {  
            try {  
                this.conn.close();  
                this.pst.close();  
            } catch (SQLException e) {  
                e.printStackTrace();  
            }  
        }  
    }

再写一个Demo.java来执行相关查询操做

Demo.java

import java.sql.ResultSet;  
    import java.sql.SQLException;  
      
    public class Demo {  
      
        static String sql = null;  
        static DBHelper db1 = null;  
        static ResultSet ret = null;  
      
        public static void main(String[] args) {  
            sql = "select *from stuinfo";//SQL语句  
            db1 = new DBHelper(sql);//建立DBHelper对象  
      
            try {  
                ret = db1.pst.executeQuery();//执行语句，获得结果集  
                while (ret.next()) {  
                    String uid = ret.getString(1);  
                    String ufname = ret.getString(2);  
                    String ulname = ret.getString(3);  
                    String udate = ret.getString(4);  
                    System.out.println(uid + "\t" + ufname + "\t" + ulname + "\t" + udate );  
                }//显示数据  
                ret.close();  
                db1.close();//关闭链接  
            } catch (SQLException e) {  
                e.printStackTrace();  
            }  
        }  
      
    }