对于java操作mysql数据库删除一行的问题；本人菜鸟跪求

package org.demo.test;

import java.sql.*;

public class SimpleConnectMysqlDemo {

public static void main(String[] args) {

    // 驱动程序名
    String driver = "com.mysql.jdbc.Driver";

    // URL指向要访问的数据库名scutcs
    String url = "jdbc:mysql://127.0.0.1:3306/school?characterEncoding=utf-8";

    // MySQL配置时的用户名
    String user = "root";

    // MySQL配置时的密码
    String password = "root";

    // 获取当前环境编码
    // System.out.println(Charset.defaultCharset());

    try {
        Class.forName(driver);

        // 获取数据库连接
        Connection conn = DriverManager.getConnection(url, user, password);
        if (!conn.isClosed())
            System.out.println("Succeeded connecting to the Database!");

        // statement用来执行SQL语句
        Statement statement = conn.createStatement();


        String sql1 = "select id,username,birthday,image from user";
        String hehe ="insert into user( id,username,birthday,image) "
                + "values(NULL,'张三丰','2011/1/1','190.12')";
        //String sql2="delete * from table where name='name'";
        //String haha="delete * from school where name='张三丰'";
        int tag = statement.executeUpdate(hehe);

        // 结果集
        ResultSet rs = statement.executeQuery(sql1);

        while (rs.next()) {

            System.out.println(rs.getString("id") + 
                    "\t" + rs.getString("username")+ 
                    "\t" + rs.getString("birthday"));
        }

        // 关闭数据库，释放资源
        close(rs, statement, conn);

    } catch (ClassNotFoundException e) {        
        e.printStackTrace();
    } catch (SQLException e) {
        e.printStackTrace();
    }

}

/**
 * 释放资源，释放资源的顺序应该按照释放结果集，释放Statement，释放数据库连接的顺序并且，为了不占用太多的资源，
 * 数据库连接建立到释放的时间应该尽量短。
 * 
 * @param rs
 * @param st
 * @param con
 */
public static void close(ResultSet rs, Statement st, Connection con) {
    if (rs != null) {
        try {
            rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    if (st != null) {
        try {
            st.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    if (con != null) {
        try {
            con.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

}

delete from table where name = xxx