mybatis复习笔记2——基本CRUD操作（IDEA版本）

朴灿烈づ我的快乐病毒、 2023-01-07 07:09 102阅读 0赞

### 搭建mybatis环境请看笔记一：[https://blog.csdn.net/weixin\_44841312/article/details/112591043][https_blog.csdn.net_weixin_44841312_article_details_112591043] ###

# 一，整体的结构： #

# ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDg0MTMxMg_size_16_color_FFFFFF_t_70][] #

# 二，IStudent #

package com.itcast.dao;
    
    import com.itcast.dao.domin.QueryVo;
    import com.itcast.dao.domin.Student;
    
    import java.util.List;
    /**学生的持久层接口*/
    public interface IStudent {
        List<Student> findAll();
    
        /**
         * 保存操作
         * @param student
         */
        void saveStudent(Student student);
        /**
         * 更新操作
         */
        void updateStudent(Student student);
    
        /**
         * 删除操作
         * @param sno
         */
        void deleteStudent(String sno);
    
        /**
         * 根据Sno查询学生
         * @param sno
         */
        Student findBySno(String sno);
        /**
         * 根据Sno查询学生
         * @param keyWord
         */
        List<Student> findByKeyWord(String keyWord);
    
        /**
         * 统计学生数量
         * @return
         */
        int count();
    
        /**
         * 间接查询
         * @return
         */
        List<Student> findQueryVo(QueryVo queryVo);
    
    }

# 三，IStudentDao.xml #

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper
            PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
            "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.itcast.dao.IStudent">
    
        <resultMap id="studentMap" type="com.itcast.dao.domin.Student">
    
            <id property="Sno" column="Sno"></id>
    
            <result property="Sname" column="Sname"></result>
            <result property="Ssex" column="Ssex"></result>
            <result property="Sage" column="Sage"></result>
            <result property="Sdept" column="Sdept"></result>
        </resultMap>
    
    
    
        <select id="findAll"  resultMap="studentMap" >
        select * from student
      </select>
    
        <select id="findBySno" parameterType="java.lang.String" resultType="com.itcast.dao.domin.Student">
            select * from student where Sno=#{Sno}
        </select>
        
        <select id="findByKeyWord" parameterType="java.lang.String" resultType="com.itcast.dao.domin.Student">
            select * from student where Sname like #{keyword}
        </select>
        
        <select id="count" resultType="java.lang.Integer">
            select count(Sno) from student
        </select>
    
        <select id="findQueryVo" parameterType="com.itcast.dao.domin.QueryVo" resultType="com.itcast.dao.domin.Student">
            select * from student where Sname like #{student.Sname}
        </select>
    
    
    
    
    
    
        <insert id="saveStudent" parameterType="com.itcast.dao.domin.Student">
            insert into student(Sno,Sname,Ssex,Sage,Sdept) values (#{Sno},#{Sname},#{Ssex},#{Sage},#{Sdept})
        </insert>
    
        <update id="updateStudent" parameterType="com.itcast.dao.domin.Student">
            update student set Sno=#{Sno},Sname=#{Sname},Ssex=#{Ssex},Sage=#{Sage},Sdept=#{Sdept} where Sno=#{Sno}
        </update>
        <delete id="deleteStudent" parameterType="java.lang.String">
            delete from student where Sno=#{Sno}
        </delete>
    </mapper>

# 四，javaBean数据载体的实体类 #

# 1，student #

import com.itcast.dao.domin.QueryVo;
    import com.itcast.dao.domin.Student;
    import com.itcast.dao.IStudent;
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.List;
    
    public class StudentTest {
        InputStream in;
        SqlSessionFactoryBuilder builder;
        SqlSessionFactory factory;
        SqlSession session;
        IStudent student;
    
        @Before
        public void Init() throws IOException {
            //1,读取配置文件，得到sqlMapConfig.xml文件流，用于构建SqlSessionFactory的工厂对象
             in= Resources.getResourceAsStream("sqlMapConfig.xml");
            //2,创建SqlSessionFactory工厂
             builder= new SqlSessionFactoryBuilder();//SqlSessionFactory的实现类
             factory= builder.build(in);//SqlSessionFactory是一个接口，不可以直接实例化
            //3,使用工厂生产SqlSession对象
             session=factory.openSession();
            //4,使用session创建dao代理对象
             student=session.getMapper(IStudent.class);
        }
        @After
       public void closeAll() throws IOException {
            session.close();
            in.close();
        }
        @Test
        public void findAll() throws IOException {
            Init();
            List<Student> students=student.findAll();
            for (Student stu : students){
                System.out.println(stu);
            }
            closeAll();
        }
        @Test
        public void findBySno() throws IOException {
            Init();
            Student students=student.findBySno("20175125");
            System.out.println(students);
            closeAll();
        }
        @Test
        public void findByKeyWord() throws IOException {
            Init();
            List<Student> students=student.findByKeyWord("%江%");
            for (Student stu : students){
                System.out.println(stu);
            }
            closeAll();
        }
        @Test
        public void findQueryVo() throws IOException {
            Init();
            QueryVo queryVo=new QueryVo();
            Student s=new Student();
            s.setSname("%江%");
            queryVo.setStudent(s);//将queryVo于student关联起来
            List<Student> students=student.findQueryVo(queryVo);
            for (Student stu : students){
                System.out.println(stu);
            }
            closeAll();
        }
        @Test
        public void count() throws IOException {
            Init();
            int number=student.count();
            System.out.println(number);
    
            closeAll();
        }
        @Test
       public void saveStudent() throws IOException {
            Init();
            Student s=new Student();
            s.setSage(121);
            s.setSdept("csa");
            s.setSname("xiaokangaaa");
            s.setSno("1212131");
            s.setSsex("男");
            student.saveStudent(s);
            session.commit();
            closeAll();
        }
        @Test
        public void updateStudent() throws IOException {
            Init();
            Student s=new Student();
            s.setSage(11);
            s.setSdept("cs");
            s.setSname("小米");
            s.setSno("1212131");
            s.setSsex("女");
            student.updateStudent(s);
            session.commit();
            closeAll();
        }
        @Test
        public void deleteStudent() throws IOException {
            Init();
            student.deleteStudent("");
            session.commit();
            closeAll();
        }
    
    
    }

# 2，QueryVo #

package com.itcast.dao.domin;
    
    public class QueryVo {
        private Student student;
    
        public Student getStudent() {
            return student;
        }
    
        public void setStudent(Student student) {
            this.student = student;
        }
    }

# 五，测试类StudentTest #

# 六，数据库stu，数据表student #

# ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDg0MTMxMg_size_16_color_FFFFFF_t_70 1][] #

# 七，结果示例 #

# ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDg0MTMxMg_size_16_color_FFFFFF_t_70 2][] #

[https_blog.csdn.net_weixin_44841312_article_details_112591043]: https://blog.csdn.net/weixin_44841312/article/details/112591043
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