关于mybatismapper的问题

测试

import mapper.StudentMapper;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import pojo.Student;
import util.mybatisunti;


public class Tesyt {

    @Test
    public void testupdate(){
        SqlSession sqlSession = mybatisunti.openSqlSession();
        StudentMapper mapper = sqlSession.getMapper(StudentMapper.class);
        Student student = new Student("0013","杨六","15","深圳","96");
        int cout = mapper.update(student);
        System.out.println(cout);
    }


    @Test
    public void testdelect(){
        SqlSession sqlSession = mybatisunti.openSqlSession();
        StudentMapper mapper = sqlSession.getMapper(StudentMapper.class);
        int cout = mapper.delect("0013");
        System.out.println(cout);
    }
}

mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">


<mapper namespace="mapper.StudentMapper">
    <update id="update" >
        update
            students
        set
            name=#{name},age=#{age},nativee=#{nativee},grage=#{grage}
        where
            sno = #{sno}
    update>

    <delete id="delect">
        delete from students where sno=#{sno}
    delete>


mapper>

接口

package mapper;

import pojo.Student;

public interface StudentMapper {
    //插入
    int inset(Student stu);

    //查询
    Student select(String  sno);

    //删除
    int  delect(String  sno);


    //更新
    int update(Student stu);

}

数据库的数据并没有删除，这个原因是什么？

mybatisunti这个类的代码截图