JDBC例子

package JDBC_Test;

import com.mysql.cj.jdbc.Driver;
import org.omg.CosNaming.NamingContextExtPackage.StringNameHelper;

import java.sql.*;

public class demo1 {
    public static String strUrl = "jdbc:mysql://localhost:3306/school";
    public static String strName = "root";
    public static String strPassword = "123456";

    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        //加载驱动
        //DriverManager.registerDriver(new com.mysql.jdbc.Driver());
        Class.forName("com.mysql.jdbc.Driver");

        //新建连接    ?useUnicode=true&characterEncoding=utf8&useSSL=true

        // connection 数据库对象(数据库自动提交，回滚)
        Connection connection = DriverManager.getConnection(strUrl, strName, strPassword);

        // SQL的执行对象 statement执行sql的对象
        Statement statement = connection.createStatement();
        //statement.execute(); 执行所有sql语句 效率低
        //statement.executeUpdate(); 执行update insert delete操作 返回受影响行数
        String strSqlBuf = "select * from student";
        //结果集，封装了所有的查询对象
        ResultSet resultSet = statement.executeQuery(strSqlBuf);
        /*resultSet.getObject(); 获取不指定类型数据
        resultSet.getInt();
        resultSet.getFloat();
        resultSet.getFloat();
        resultSet.beforeFirst();移动到最前面
        resultSet.afterLast(); 移动到最后面
         resultSet.absolute();移动到指定行
        */

        while (resultSet.next()) {
            System.out.println("id= " + resultSet.getObject("studentno"));
            System.out.println("name= " + resultSet.getObject("studentname"));
            System.out.println("sex= " + resultSet.getObject("sex"));
            System.out.println("gradeid= " + resultSet.getObject("gradeid"));
            System.out.println("phone= " + resultSet.getObject("phone"));

            System.out.println("__________________________________________________");
        }
        //释放驱动
        resultSet.close();
        statement.close();
        connection.close();
    }
}