打通Java与MySQL的桥梁——jdbc

作者：@syske
本文为作者原创，转载请注明出处：https://www.cnblogs.com/caoleiCoding/p/6537652.html

实现的基本步骤：

　　1、加载驱动程序：　　　　

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

　　2、获得数据可连接：　　

private static final String url = "jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8&useSSL=false"; //数据库地址
private static final String usename = "root";
private static final String password = "root"; //数据库密码
 
Connection connection = DriverManager.getConnection(URL,USER,PASSWORD);　

　　其中，url中jdbc表示连接方式，mysql表示数据库软件为mysql，localhost表示数据库地址，3306表示数据库端口，shopping表示数据库名称。

　　3、通过数据库的连接操作数据库，实现增删改查　　

1	`Statement statement = connection.createStatement();`

1	`ResultSet resultSet = statement.executeQuery("SELECT * FROM goods;");` `//用于执行数据库查询<br><br>ResultSet resultSet = statement.executeUpdate("");//用于执行数据库更新`

　　另外一种sql语句执行方法:

1 2	`PreparedStatement pStatement = connection.prepareStatement("");` `//编译sql代码` `pStatement.execute();` `//执行sql代码`

　　下面是一个完整的测试代码：

package util;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
 
public class DBHelper {
     
    private static String driver = "com.mysql.jdbc.Driver";   //数据库驱动
    //连接数据库的URL地址
    private static final String url = "jdbc:mysql://localhost:3306/shopping?useUnicode=true&characterEncoding=UTF-8&useSSL=false";
    private static final String usename = "root";
    private static final String password = "root"; //数据库密码
     
    private static Connection connection =null;
    //静态代码块负责加载驱动
    static{//静态块中的代码会优先被执行
        try {
            Class.forName(driver);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
     
    //单例模式返回数据库连接对象
    public static Connection getConnection(){
        if(connection==null){
            try {
                connection = DriverManager.getConnection(url,usename,password);
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return connection;
        }
        return connection;
    }
    public static void main(String[] args) {
        ResultSet resultSet = null;
        try{
        Connection connection = DBHelper.getConnection();
        Statement statement =  connection.createStatement();
         resultSet = statement.executeQuery("SELECT * FROM goods;");         
         while(resultSet.next()){
        System.out.println(resultSet.getString("name"));
         }
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}