1、输入参数（POJO包装类）：
（1）POJO包装类：
public class QueryVo implements Serializable {
private static final long serialVersionUID = 1L;
private Student student;
public Student getStudent() {
return student;
}
public void setStudent(Student student) {
this.student = student;
}
}
需要实现序列化接口，用于实现序列化（对象转化为二进制）与反序列化（二进制转换为对象）。
（2）配置mapper.xml配置文件：
<select id="findStudentByQueryVo" parameterType="QueryVo" resultType="pers.zhb.pojo.Student">
select * from student where sname like "%"#{student.sname}"%"
</select>
（3）创建接口：
public interface StudentMapper {
Student findStudentById(Integer studentno);
List<Student> findStudentByQueryVo(QueryVo vo);
}
（4）测试：
public void findStudentByQueryVo() throws Exception {
//加载核心配置文件
String resource = "sqlMapConfig.xml";
InputStream in = Resources.getResourceAsStream(resource);
//创建SqlSessionFactory
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
//创建SqlSession
SqlSession sqlSession = sqlSessionFactory.openSession();
//SqlSEssion帮我生成一个实现类 （给接口）
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
QueryVo queryVo=new QueryVo();
Student student=new Student();
student.setSname("z");
queryVo.setStudent(student);
List<Student> s = studentMapper.findStudentByQueryVo(queryVo);
for(Student ss:s){
System.out.println(s);
}
}
2、输出参数
（1）接口：
public interface StudentMapper {
Integer countStudent();
}
（2）配置文件：
<select id="countStudent" resultType="Integer">
select count(*) from student
</select>
（3）测试：
public void countStudent() throws Exception {
//加载核心配置文件
String resource = "sqlMapConfig.xml";
InputStream in = Resources.getResourceAsStream(resource);
//创建SqlSessionFactory
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
//创建SqlSession
SqlSession sqlSession = sqlSessionFactory.openSession();
//SqlSEssion帮我生成一个实现类 （给接口）
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
Integer countStudent = studentMapper.countStudent();
System.out.println(countStudent);
}
3、输出类型：ResultMap
（1）书写POJO：
public class Student implements Serializable {
private static final long serialVersionUID = 1L;
private String snumber;
private String sname;
private String sex;
private String birthday;
private String classno;
private String point;
private String phone;
private String email;
public String getSnumber() {
return snumber;
}
public void setSnumber(String snumber) {
this.snumber = snumber;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getBirthday() {
return birthday;
}
public void setBirthday(String birthday) {
this.birthday = birthday;
}
@Override
public String toString() {
return "Student [snumber=" + snumber + ", sname=" + sname + ", sex="
+ sex + ", birthday=" + birthday + ", classno=" + classno
+ ", point=" + point + ", phone=" + phone + ", email=" + email
+ "]";
}
public String getClassno() {
return classno;
}
public void setClassno(String classno) {
this.classno = classno;
}
public String getPoint() {
return point;
}
public void setPoint(String point) {
this.point = point;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
（2）接口：
public interface StudentMapper {
List<Student> selectAllStudent();
}
（3）配置文件：
<select id="selectAllStudent" resultType="pers.zhb.pojo.Student">
select * from student
</select>
（4）书写测试类：
public void selectAllStudent() throws Exception {
//加载核心配置文件
String resource = "sqlMapConfig.xml";
InputStream in = Resources.getResourceAsStream(resource);
//创建SqlSessionFactory
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
//创建SqlSession
SqlSession sqlSession = sqlSessionFactory.openSession();
//SqlSEssion帮我生成一个实现类 （给接口）
StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
List<Student> students = studentMapper.selectAllStudent();
for(Student student:students){
System.out.println(student);
}
}
（5）输出结果：
DEBUG [main] - Find JAR URL: file:/D:/IdeaProjects/MybatisDemo/web/WEB-INF/classes/pers/zhb/mapper/StudentMapper.xml
DEBUG [main] - Not a JAR: file:/D:/IdeaProjects/MybatisDemo/web/WEB-INF/classes/pers/zhb/mapper/StudentMapper.xml
DEBUG [main] - Reader entry: <?xml version="1.0" encoding="UTF-8" ?>
DEBUG [main] - Checking to see if class pers.zhb.mapper.StudentMapper matches criteria [is assignable to Object]
DEBUG [main] - Opening JDBC Connection
DEBUG [main] - Created connection 517210187.
DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@1ed4004b]
DEBUG [main] - ==> Preparing: select * from student
DEBUG [main] - ==> Parameters:
DEBUG [main] - <== Total: 8
Student [snumber=null, sname=zhai, sex=男, birthday=1998-11-11, classno=tx171, point=890, phone=1234567890, email=null]
Student [snumber=null, sname=zhai2, sex=男, birthday=1998-11-11, classno=tx171, point=893, phone=19837372533, email=null]
Student [snumber=null, sname=zhai3, sex=男, birthday=1998-11-11, classno=tx171, point=892, phone=19837372534, email=null]
Student [snumber=null, sname=zhai3, sex=男, birthday=1998-11-11, classno=tx101, point=892, phone=19837372534, email=null]
Student [snumber=null, sname=qwerr, sex=男, birthday=1998-11-11, classno=tx101, point=892, phone=19837372534, email=null]
Student [snumber=null, sname=jiayou, sex=男, birthday=1998-11-11, classno=tx101, point=892, phone=19837372534, email=null]
Student [snumber=null, sname=null, sex=null, birthday=null, classno=2, point=null, phone=null, email=null]
Student [snumber=null, sname=null, sex=null, birthday=null, classno=2, point=null, phone=null, email=null]
可以看到snumber列的数据都为空，只是因为POJO中的列名与数据库中的列名不一致导致的（在sql类型处理器不能根据属性名查找数据库中的数据）。因为resultType可以指定将查询结果映射为pojo，但需要pojo的属性名和sql查询的列名一致方可映射成功。
（6）resultMap
结果集映射，映射为Student：
<id property="studentno" column="studentno"></id>
在
<resultMap id="result" type="Student">
<result column="studentno" property="snumber"></result>
</resultMap>
<select id="selectAllStudent" resultMap="result">
select * from student
</select>
可以采用resultMap的方式，即使POJO中的属性与数据库的字段不一致，依旧能够查询成功。因为resultMap将字段名和属性名作一个对应关系 ，resultMap实质上还需要将查询结果映射到pojo对象中。