idea

接口：

 //04.查询学生姓名中包含"星星"的 ，并且年里在20岁以上的学生信息
    public List<StudentInfo> findStudentListLike(StudentInfo info);
    //05.查询姓名中包含“雨”，并且年龄>20的学生信息
    public  List<StudentInfo> findStudentsByCondition(Map<String,Object> map);
    //05.查询姓名中包含“雨”，并且年龄>20的学生信息
    public  List<StudentInfo> findStudentsByConditionMutliArgs(String stuName,int stuAge);

    //06.智能标签if
    public List<StudentInfo> findByIf(StudentInfo stu);

    //06.智能标签choose
    public List<StudentInfo> findByChoose(StudentInfo stu);

    //07.智能标签foreach
    public  List<StudentInfo> findByForeachArray(int[] ids);
    //07.智能标签foreach List<Integer>
    public  List<StudentInfo> findByForeachList(List<Integer> list);

    //07.智能标签foreach List<StudentInfo>
    public  List<StudentInfo> findByForeachListStudent(List<StudentInfo> list);

小配置·：

<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE mapper        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"        "http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mapper namespace="bdqn.dao.Departmentdao">

 <!--模糊查询-->
    <select id="findStudentListLike" resultType="StudentInfo">
        <!--select * from studentinfo where stuname like concat('%',#{stuName},'%') and stuAge>#{stuAge}-->
            select * from studentinfo where stuname like '%${stuName}%' and stuAge>#{stuAge}
    </select>

    <!--多条件查询-->
    <select id="findStudentsByCondition" resultType="StudentInfo">
         select * from  studentinfo where stuname like '%' #{stuName} '%' and stuAge>#{stuAge}
    </select>

    <!--多条件查询使用索引-->
    <select id="findStudentsByConditionMutliArgs" resultType="StudentInfo">
        select * from  studentinfo where stuname like '%' #{0} '%' and stuAge>#{1}
    </select>

    <!--智能标签foreach List-->
    <select id="findByForeachListStudent" resultType="StudentInfo">
        select * from studentinfo
        <where>
            <if test="list.size>0">
                stuid in
                <foreach collection="list" open="(" close=")" separator="," item="stu">
                    #{stu.stuId}
                </foreach>
            </if>
        </where>
    </select>
    <!--智能标签foreach List-->
    <select id="findByForeachList" resultType="StudentInfo">
        select * from studentinfo
        <where>
            <if test="list.size>0">
                stuid in
                <foreach collection="list" open="(" close=")" separator="," item="stuno">
                    #{stuno}
                </foreach>
            </if>
        </where>
    </select>

    <!--智能标签foreach Array-->
    <select id="findByForeachArray" resultType="StudentInfo">
        select * from studentinfo
        <where>
            <if test="array.length>0">
                stuid in
                <foreach collection="array" open="(" close=")" separator="," item="stuno">
                    #{stuno}
                </foreach>
            </if>
        </where>
    </select>

    <!--智能标签choose-->
    <select id="findByChoose" resultType="StudentInfo">
        select * from studentinfo
        <where>
            <choose>
                <when test="stuName!=null">
                    and stuName like '%' #{stuName} '%'
                </when>
                <when test="stuAge!=null">
                    and stuAge>#{stuAge}
                </when>
                <otherwise>
                     and 1=2
                </otherwise>
            </choose>
        </where>
    </select>

    <!--智能标签if-->
    <select id="findByIf" resultType="StudentInfo">
        select * from studentinfo
        <where>
            <if test="stuName!=null"><!--用户录入的姓名字段-->
                 and stuName like '%' #{stuName} '%'
            </if>
            <if test="stuAge!=null">
                and stuAge>#{stuAge}
            </if>
        </where>
    </select>

</mapper>

测试类：

package cn.happy.test;
import cn.happy.dao.IDeptDAO;import cn.happy.dao.IStudentInfoDAO;import cn.happy.entity.Dept;import cn.happy.entity.Emp;import cn.happy.entity.StudentInfo;import cn.happy.util.MyBatisUtil;import org.apache.ibatis.session.SqlSession;import org.junit.Test;
import java.util.*;
/** * Created by Happy on 2017-07-09. */public class MyBatisTest0712 {    //07.多表连接查询 一对多  单条SQL    @Test    public void testOneToMany(){        SqlSession session= MyBatisUtil.getSession();        IDeptDAO dao = session.getMapper(IDeptDAO.class);        Dept dept = dao.getEmpsByDeptNo(5);        System.out.println(dept.getDeptName());        for (Emp emp:dept.getEmps()) {            System.out.println(emp.getEmpName());        }
        session.close();    }
    //06.智能标签Foreach List<StudentInfo>    @Test    public void testForeachListStudent(){        SqlSession session= MyBatisUtil.getSession();        IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);        List<StudentInfo> list=new ArrayList<StudentInfo>();        StudentInfo s1=new StudentInfo();        s1.setStuId(2);        StudentInfo s2=new StudentInfo();        s2.setStuId(5);        list.add(s1);        list.add(s2);        List<StudentInfo> list2 = dao.findByForeachListStudent(list);        for (StudentInfo stuinfo:list2) {
            System.out.println(stuinfo.getStuName());        }        session.close();    }
    //06.智能标签Foreach List<Integer>    @Test    public void testForeachList(){        SqlSession session= MyBatisUtil.getSession();        IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);        List<Integer> list=new ArrayList<Integer>();        list.add(2);        list.add(5);        List<StudentInfo> list2 = dao.findByForeachList(list);        for (StudentInfo stuinfo:list2) {
            System.out.println(stuinfo.getStuName());        }        session.close();    }
    //06.智能标签Foreach array    @Test    public void testForeachArray(){        SqlSession session= MyBatisUtil.getSession();        IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);        int[] ids={2,5};        List<StudentInfo> list = dao.findByForeachArray(ids);        for (StudentInfo stuinfo:list) {
            System.out.println(stuinfo.getStuName());        }        session.close();    }
    //05.智能标签choose    @Test    public void testChoose(){        SqlSession session= MyBatisUtil.getSession();        IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);        StudentInfo stu=new StudentInfo();        // stu.setStuName("雨");       // stu.setStuAge(20);        List<StudentInfo> list = dao.findByChoose(stu);        for (StudentInfo stuinfo:list) {
            System.out.println(stuinfo.getStuName());        }        session.close();    }
    //05.智能标签if    @Test    public void testIf(){        SqlSession session= MyBatisUtil.getSession();        IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);        StudentInfo stu=new StudentInfo();       // stu.setStuName("雨");       stu.setStuAge(20);        List<StudentInfo> list = dao.findByIf(stu);        for (StudentInfo stuinfo:list) {
            System.out.println(stuinfo.getStuName());        }        session.close();    }
    //04.多条件查询    @Test    public void testSelectLikeMulti(){        SqlSession session= MyBatisUtil.getSession();        IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);
        List<StudentInfo> list = dao.findStudentsByConditionMutliArgs("雨",20);        for (StudentInfo stu:list) {            System.out.println(stu.getStuName());        }        session.close();    }
    //04.多条件查询    @Test    public void testSelectLike(){        SqlSession session= MyBatisUtil.getSession();        IStudentInfoDAO dao = session.getMapper(IStudentInfoDAO.class);        Map<String,Object> map=new HashMap<String,Object>();        map.put("stuName","雨");        map.put("stuAge",20);        List<StudentInfo> list = dao.findStudentsByCondition(map);        for (StudentInfo stu:list) {            System.out.println(stu.getStuName());        }        session.close();    }
}