MyBatisMyBatis存储过程、MyBatis分页、MyBatis一对多增删改查操作

一、用到的实体类如下：

Student.java

 package com.company.entity;

 import java.io.Serializable;
 import java.util.Date;

 public class Student implements Serializable{

     private static final long serialVersionUID = 1L;
     private int id;
     private String name;
     private Date birth;
     private Group group;


     public Group getGroup() {
         return group;
     }
     public void setGroup(Group group) {
         this.group = group;
     }
     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public Date getBirth() {
         return birth;
     }
     public void setBirth(Date birth) {
         this.birth = birth;
     }
     @Override
     public String toString() {
         return "Student [birth=" + birth + ", group=" + group + ", id=" + id
                 + ", name=" + name + "]";
     }


 }

Group.java

 package com.company.entity;

 import java.util.List;

 public class Group {
     private int id;
     private String name;
     private String position;
     private List<Student> students;


     public List<Student> getStudents() {
         return students;
     }
     public void setStudents(List<Student> students) {
         this.students = students;
     }
     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getPosition() {
         return position;
     }
     public void setPosition(String position) {
         this.position = position;
     }
     @Override
     public String toString() {
         return "Group [id=" + id + ", name=" + name + ", position=" + position
                 + "]";
     }

 }

 

二、实体对应的表结构

student表:

create table student(

id  int primary key,

name varchar(20),

birth date,

group_id int references g_group(g_id));

 

g_group表:

create  table g_group(

g_id int primary key,

g_name varchar(20),

g_position varchar(30));

 

sequence:

create sequence student_id_sequence;

create sequence group_id_sequence;

 

三、Student和Group的映射文件如下，你可以在映射文件中找到，关于MyBatis的增删改查操作，MyBatis调用存储过程，MyBatis分页以及MyBatis对一对一、多对多的处理

xml文件中都标有注释，看的时候配合下面的具体实现看，虽然有点乱

 

student.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.company.dao.IStudentDAO">

     <!-- mybatis缓存 -->
     <cache eviction="LRU" flushInterval="600000" size="1024" readOnly="false" />

     <!-- sql标签用来定义一些可以被重用的sql语句或字段或片段等 -->
     <sql id="studentColumns">select id,name,birth from student</sql>

     <!-- 此处获得多对一的关系 ,但就单条记录而言却是一对一的关系，所以一对一的写法跟此相同-->
     <resultMap type="Student" id="getStudentAndGroup" >
         <id column="id" property="id"/>
         <result column="name" property="name"/>
         <result column="birth" property="birth"/>
         <association property="group" column="group_id" javaType="Group">
             <id column="g_id" property="id"/>
             <result column="g_name" property="name"/>
             <result column="g_position" property="position"/>
         </association>
     </resultMap>
     <select id="many2one" resultMap="getStudentAndGroup" parameterType="int" >
         select s.id,s.name,s.birth,s.group_id,g.g_id,g.g_name,g.g_position
         from student s
         left join g_group g on s.group_id = g.g_id
         where s.id = #{id}
     </select>


     <!-- 意图是获得一个学生，并且获得该学生所属的组，跟上面的意思差不多 ,用association的select属性-->
     <!-- 于上面的相比个人感觉上面的效率要高些，因为上面只有一条sql语句 -->
     <resultMap type="Student" id="getStudentAndGroupUseSelectMap">
         <id column="id" property="id"/>
         <result column="name" property="name"/>
         <result column="birth" property="birth"/>
         <association property="group" column="group_id" javaType="Group" select="selectGroup" />
     </resultMap>
     <select id="getStudentAndGroupUseSelect" resultMap="getStudentAndGroupUseSelectMap" parameterType="int">
         select *
         from student
         where id = #{id}
     </select>
     <select id="selectGroup" resultType="Group" parameterType="int" flushCache="false" useCache="true"><!-- 此处实用缓存 -->
         select g_id as id, g_name as name, g_position as position
         from g_group
         where g_id = #{id}
     </select>

     <!-- 动态sql语句 的测试dynamic sql-->
     <select id="getStudentBySomeCondition" parameterType="Student" resultType="Student">
         select *
         from student
         <where>
             <if test="id != null">
                 id>2
             </if>
             <if test="name != null">
                 and name like '%g%'
             </if>
         </where>
     </select>

     <!-- MyBatis调用存储过程 -->
     <resultMap type="Student" id="studentMap">
         <id column="id" property="id"/>
         <result column="name" property="name"/>
         <result column="birth" property="birth"/>
     </resultMap>
     <select id="getAllUser" statementType="CALLABLE" >
         {call get_all_student(#{students ,mode=OUT, jdbcType=CURSOR, javaType=ResultSet, resultMap=studentMap} )}
     </select>


     <!-- MyBatis向student表中插入一条数据 -->
     <insert id="add" parameterType="Student" keyColumn="id">
         <selectKey keyProperty="id" order="BEFORE" resultType="int">
             select stu_id_sequence.nextval from dual
         </selectKey>
         insert into student(id,name,birth) values(#{id},#{name},#{birth})
     </insert>

     <!-- 根据id获得学生的信息 -->
     <select id="getById" parameterType="int" resultType="Student">
         <include refid="studentColumns"/> where id=#{id}
     </select>

     <!-- 此处的实现方法是一个分页的原型,请查看IStudentDAOImpl.java中的调用方法 -->
     <select id="getAllStudent" resultMap="studentMap">
         <include refid="studentColumns"/> order by id<!--此处是引用了上面预定义好的sql语句-->
     </select>


 </mapper>

group.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.company.dao.IGroupDAO">



     <resultMap type="Group" id="groupResultMap" >
         <id column="g_id" property="id"/>
         <result column="g_name" property="name"/>
         <result column="g_position" property="position"/>
     </resultMap>
     <sql id="getALl">select * from</sql>

     <!-- 意图想通过获得组和组中的所有student,此处相当于one2many -->
     <resultMap type="Group" id="getGroupAndStudents">
         <id column="g_id" property="id"/>
         <result column="g_name" property="name"/>
         <result column="g_position" property="position"/>
         <collection property="students" ofType="Student" column="group_id"><!-- 注意此处的group_id是student表的外键 -->
             <id column="id" property="id"/>
             <result column="name" property="name"/>
             <result column="birth" property="birth"/>
         </collection>
     </resultMap>






     <select id="getById" parameterType="int" resultMap="getGroupAndStudents">
         select g.g_id,g.g_name,g.g_position,s.id,s.name,s.birth ,s.group_id
         from g_group g
         left join student s on g.g_id = s.group_id
         where g.g_id = #{id}
     </select>

     <!--
     <select id="getById" parameterType="int" resultType="Group">
         select g_id as id, g_name as name, g_position as position from g_group where g_id=#{id}
     </select>
      -->
     <select id="getByIdResultMap" parameterType="_int" resultMap="groupResultMap">
         select g_id ,g_name, g_position  from g_group where g_id=#{id}
     </select>
     <delete id="deleteById" parameterType="_int" timeout="1000">
         delete from g_group where g_id=#{id}
     </delete>
     <insert id="add" parameterType="Group">
         insert into g_group(g_id, g_name, g_position)
         values(#{id}, #{name}, #{position})
     </insert>

 </mapper>

 

四、接口IStudentDAO.java和IGroupDAO.java中定义了IStudentDAOImpl.java和IGroupDAOImpl.java中需要实现的方法

IStudentDAO.java

 package com.company.dao;

 import java.util.List;

 import com.company.entity.Student;

 public interface IStudentDAO {
     /**
      * 增加一个学生
      * @param student
      */
     public void add(Student student);

     /**
      * 根据学生的Id删除学生
      * @param id
      */
     public void deleteById(int id);

     /**
      * 通过学生的id获得学生的信息
      * @param id
      * @return
      */
     public Student getById(int id);

     /**
      * 更新学生信息
      * @param student
      */
     public void update(Student student);

     /**
      * 此处是MyBatis的分页查询
      * @return
      */
     public List<Student> getAllStudent();

     /**
      * 多对一
      * @param id
      * @return
      */
     public Student many2one(int id);

     /**
      * 获得学生的信息，并且获得该学生所属的组的信息
      * @param id
      * @return
      */
     public Student getStudentAndGroupUseSelect(int id);

     /**
      * 动态sql
      * @param student
      * @return
      */
     public List<Student> getStudentBySomeCondition(Student student);

     /**
      * 获得所有的学生信息，此处是调用在数据库中存储过程
      * @return
      */
     public List<Student> getAllUser();
 }

对应的实现类IStudentDAOImpl.java如下：

 package com.company.dao.impl;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 import org.apache.ibatis.session.RowBounds;
 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;

 import com.company.dao.IStudentDAO;
 import com.company.entity.Student;
 import com.company.util.DBUtil;

 public class IStudentDAOImpl implements IStudentDAO {



     public void add(Student student) {
         SqlSessionFactory sqlSessionFactory = DBUtil.getSqlSessionFactory();
         SqlSession session = sqlSessionFactory.openSession();
         try{
             IStudentDAO dao = session.getMapper(IStudentDAO.class);
             dao.add(student);
             session.commit();
         }catch(Exception e){
             e.printStackTrace();
         }finally{
             session.close();
         }
     }

     public void deleteById(int id) {

     }

     public Student getById(int id) {
         SqlSessionFactory sqlSessionFactory = DBUtil.getSqlSessionFactory();
         SqlSession session = sqlSessionFactory.openSession();
         Student student = null;
         try{
             IStudentDAO dao = session.getMapper(IStudentDAO.class);
             student = dao.getById(id);
         }catch(Exception e){
             e.printStackTrace();
         }finally{
             session.close();
         }
         return student;
     }

     public void update(Student student) {

     }


     public List<Student> getStudentsByGroupId(int groupId) {
         return null;
     }

     /**
      * 测试selectList，分页的原型
      * @author king
      * @return students
      * @serialData 2011-7-29
      */
     public List<Student> getAllStudent() {
         SqlSessionFactory sqlSessionFactory = DBUtil.getSqlSessionFactory();
         SqlSession session = sqlSessionFactory.openSession();
         List<Student> students = new ArrayList<Student>();
         try{
             RowBounds rb = new RowBounds(1,6);//RowBounds的下标是从0开始，表示第一条记录，此表示从第二条记录开始，取6条记录
             students = session.selectList("com.company.dao.IStudentDAO.getAllStudent", null, rb);
         }catch(Exception e){
             e.printStackTrace();
         }finally{
             session.close();
         }
         return students;
     }

     public Student many2one(int id) {
         SqlSessionFactory sqlSessionFactory = DBUtil.getSqlSessionFactory();
         SqlSession session = sqlSessionFactory.openSession();
         Student student = null;
         try{
             IStudentDAO dao = session.getMapper(IStudentDAO.class);
             student = dao.many2one(id);
         }catch(Exception e){
             e.printStackTrace();
         }finally{
             session.close();
         }
         return student;

     }

     public Student getStudentAndGroupUseSelect(int id){
         SqlSessionFactory sqlSessionFactory = DBUtil.getSqlSessionFactory();
         SqlSession session = sqlSessionFactory.openSession();
         Student student = null;
         try{
             IStudentDAO dao = session.getMapper(IStudentDAO.class);
             student = dao.getStudentAndGroupUseSelect(id);
         }catch(Exception e){
             e.printStackTrace();
         }finally{
             session.close();
         }
         return student;
     }

     public List<Student> getStudentBySomeCondition(Student student){
         SqlSessionFactory sqlSessionFactory = DBUtil.getSqlSessionFactory();
         SqlSession session = sqlSessionFactory.openSession();
         List<Student> students = new ArrayList<Student>();
         try{
             IStudentDAO dao = session.getMapper(IStudentDAO.class