MyBatis中的多条件查询讲解

 select * from student             and stuAge>#{stuAge}         and stuName LIKE '%' #{stuName} '%'                

 studentDao dao = MyBatis.getSessionTwo().getMapper(studentDao.= "z"List list="----------"+

----------zhangyu
----------zy
----------zy
----------zhang

  public List getAllStudentByLike(Map userMap);  //使用map作为参数

 <select id="getAllStudentByLike" parameterType="Map" resultType="stu">select * from student<where><choose><when test="stuName!=null"> stuName like CONCAT('%',#{stuName},'%')when><when test="stuAge!=0"> stuAge> #{stuAge}when>

    1=1

choose>where>select>

zhangyu
zy
zy
zhang

//传一组 xueshengID public List getStudentBystuId_foreach_array(Integer[] ints);




映射文件配置 
    select * from studentwhere stuId IN/*数组形式传入学生Id*/  #{stu}
        
    

  Integer[] ints = {2,3,4};
        List list = dao.getStudentBystuId_foreach_array(ints);for (student item:list) {
            System.out.println(item.getStuName());
        }

   public List getStudentBystuId_foreach_list(List list);

  select * from studentwhere stuId IN
        /*集合形式传入学生Id*/#{stu}

 studentDao dao = MyBatis.getSessionTwo().getMapper(studentDao.class);
        Integer ints = 2;
        List list = new ArrayList();
        list.add(ints);
        List stulist = dao.getStudentBystuId_foreach_list(list);
        for (student item:stulist) {
            System.out.println(item.getStuName());
        }

 public List getStudentBystuId_foreach_map(Map stuMap);

 select * from student where stuId IN
        /*集合形式传入学生Id*/    #{stu}

  Map stumap = new HashMap();
        List listStuId = new ArrayList();
        listStuId.add(2);
        listStuId.add(3);
        listStuId.add(4);
        stumap.put("stuId",listStuId);
         List list = dao.getStudentBystuId_foreach_map(stumap);
        for (student item:list
             ) {
            System.out.println(item.getStuName());
        }

 public grade getGradeById(int gradeId);

 <resultMap id="gradeMapOne" type="grade"><id column="gradeId" property="gradeId">id><result column="gradeName" property="gradeName">result><collection property="gatStudent" ofType="stu"><id column="stuUd" property="stuId">id><result column="stuName" property="stuName">result><result column="stuAge" property="stuAge">result>collection>resultMap><resultMap id="gradeMap" type="entity.grade"><id column="gradeId" property="gradeId">id><result column="gradeName" property="gradeName">result><collection property="gatStudent" ofType="student" select="getStudentById" column="gradeId">collection>    resultMap>

    select * from grade,student where grade.gradeId = student.stuGrade and gradeId = #{gradeId}select * from grade where gradeId=#{gradeId}select * from student where stuGrade = #{stuGrade}

  @Testpublic void  TestConn(){
       gradeDao dao = MyBatis.getSessionTwo().getMapper(gradeDao.class);

       grade grade = dao.getGradeById(1);       for (student item:grade.getGatStudent()            ) {
           System.out.println(item.getStuName());
       }

    }