jdbc---查询语句的使用（executeQuery）

package com.syy;<br><br>import domain.student;<br><br>import java.sql.*;<br>import java.util.ArrayList;<br><br>public class JdbcDemo3 {<br><br>    public static void main(String[] args)throws Exception {<br>        ArrayList<student> stu = getstudent();<br>        for (student stu1 : stu) {<br>            System.out.println(stu1);<br>        }<br><br>    }<br><br>    private static ArrayList<student> getstudent() throws SQLException {<br>        ArrayList<student> array = new ArrayList<student>();<br>        Connection con = null;<br>        Statement stat = null;<br>        ResultSet resultSet=null;<br>        try {<br>            //1、加载驱动类<br>            Class.forName("com.mysql.jdbc.Driver");<br>            //2、与数据库建立连接<br>            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/db4", "root", "1234");<br>            //3、获取sql语句对象<br>            stat = con.createStatement();<br>            //4、定义sql语句<br>            String sql = "select *from student ";<br>            //通过executeQuery返回结果集<br>             resultSet = stat.executeQuery(sql);<br>            //判断是否有下一个数据---获取下一个元素<br>//        resultSet.next();相当于指针下移<br>            while (resultSet.next()) {<br>                int id = resultSet.getInt("id");<br>                String name = resultSet.getString("name");<br>                String grade = resultSet.getString("grade");<br>                System.out.println(id + "\t" + name + "\t" + grade);<br>                //把字段封装成对象<br>                //创建对象<br>                student s = new student();<br>                s.setId(id);<br>                s.setName(name);<br>                s.setGrade(grade);<br>                //把对象添加到集合中<br>                array.add(s);<br><br>            }<br><br><br>        } catch (Exception e) {<br>            e.printStackTrace();<br>        } finally {<br>            if (con != null) {<br>                con.close();<br>                con = null;<br>            }<br>            if (stat != null) {<br>                    stat.close();<br>                    stat = null;<br>                }<br>            if (resultSet!=null){<br>                resultSet.close();<br><br>            }<br><br>            }<br><br>        return array;<br>    }<br><br>}

jdbc---查询语句的使用（executeQuery）

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