向数据库中存入数组数据，代码出错怎么解决

这个代码的错误怎么解决？

import java.sql.Connection;import java.sql.DriverManager;//import java.sql.Statement;import java.util.ArrayList;import java.util.List;import java.sql.PreparedStatement;import java.sql.PseudoColumnUsage;//import java.sql.SQLException;class sql1{    int id;    String name;    int age;        public sql1(int id, String name, int age) {        super();        this.id=id;        this.name=name;        this.age=age;            }    @Override    public String toString() {        return "id=" + id + ", name=" + name + ", age=" + age ;    }}public class ASDZ {    public static void main(String[] args) throws Exception {        // TODO Auto-generated method stub        List<sql1> yu=new ArrayList<>();        yu.add(new sql1(23,"ykg",12));        yu.add(new sql1(24,"ykg1",14));        yu.add(new sql1(25,"ykg2",17));//        for(sql1 i:yu) {//            System.out.println(i.toString());//        }        Class.forName("com.mysql.jdbc.Driver");        Connection con=null;        //Statement stmt=null;        PreparedStatement  ps=null;         con=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/ykg?useSSL=false","root","03579631");         //stmt= con.createStatement();         String sql="insert into yu values(?,?,?)";         ps=con.prepareStatement(sql);        for(int i=0;i<yu.size();i++) {            ps.setInt(1, yu.get(i).id);            ps.setString(2, yu.get(i).name);            ps.setInt(3, yu.get(i).age);            ps.executeUpdate(sql);                //Update        }                    if(ps!=null)                 ps.close();            if(con!=null)                con.close();    }}

运行结果及报错内容

Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?,?,?)' at line 1
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3978)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3914)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2530)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2491)
at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1552)
at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2607)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1480)
at ASDZ.main(ASDZ.java:46)