1.问题：mybatis一对一关联查询报错 org.apache.ibatis.builder.IncompleteElementException: Could not find result map，但是无轮建表，到sql查询均可以查询到，请问哪里出问题了？

• SQL建表如下：

# 创建teacher 与 class 表
CREATE TABLE IF NOT EXISTS teacher(
  t_id INT PRIMARY KEY AUTO_INCREMENT,
  t_name VARCHAR(20)
);

CREATE TABLE IF NOT EXISTS class(
  c_id INT PRIMARY KEY AUTO_INCREMENT,
  c_name VARCHAR(20),
  teacher_id INT
);
#建立一对一外键关系，这个需要学习了解
ALTER TABLE class ADD CONSTRAINT fk_teacher_id FOREIGN KEY (teacher_id) REFERENCES teacher(t_id);

#插入teacher数据
INSERT INTO teacher(t_name) VALUES('Mandy');
INSERT INTO teacher(t_name) VALUES('Chris');

#插入class数据
INSERT INTO class(c_name, teacher_id) VALUES('class_a', 1);
INSERT INTO class(c_name, teacher_id) VALUES('class_b', 2);


SELECT * FROM teacher;
SELECT * FROM class;
#级联查询表
select * from class c, teacher t where c.teacher_id=t.t_id and c.c_id=1;

java项目中maven配置：（pom.xml）

 
    
    
      log4j
      log4j
      1.2.16
    
    
    
      mysql
      mysql-connector-java
      5.1.33
    
    
    
      org.mybatis
      mybatis
      ${mybatis.version}
    
    
      junit
      junit
      4.11
      test
    
  
  
  
    mybatis
    
      
        org.mybatis.generator
        mybatis-generator-maven-plugin
        1.3.2
        
          true
          true
        
      
    
    
      
        src/main/java
        
          **/*.properties
          **/*.xml
        
        
        false
      
      
        src/main/resources
        
      
    
  

mybatis配置文档：

两个domain类：

public class Classes {
    private int id;//id===>c_id
    private String name;//name===>c_name
    private Teacher teacher;

    public Classes(int id, String name, Teacher teacher) {
        this.id = id;
        this.name = name;
        this.teacher = teacher;
    }

    public Classes() {
    }

    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 Teacher getTeacher() {
        return teacher;
    }

    public void setTeacher(Teacher teacher) {
        this.teacher = teacher;
    }

    @Override
    public String toString() {
        return "Classes {id="+id+" ,name="+name+" , teacher="+teacher+"}";
    }
}

public class Teacher {

    private int id; // id --> t_id
    private String name; // name --> t_name

    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;
    }

    @Override
    public String toString() {
        return "Teacher {id="+ id+" ,name="+ name +"}";
    }
}

ClassMapper.xml

        select *
        from class c,teacher t
        where c.teacher_id =t.t_id
        and c.c_id=#{id}
    
    
    
        
        
        
        
            
            
        
    
    

运行代码时候：

public class App 
{
    public static void main( String[] args )
    {
       SqlSession session = MyBatisUtil.getSqlSession();
       String strId = "com.mybatis.oneToone.mapping.ClassMapper.getClass1";
       Classes clazz = session.selectOne(strId,1);
        System.out.println(clazz);
    }
}

显示如下错误：
Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException:

Error querying database. Cause: org.apache.ibatis.builder.IncompleteElementException: Could not find result map com.mybatis.oneToone.domain.Teacher

Cause: org.apache.ibatis.builder.IncompleteElementException: Could not find result map com.mybatis.oneToone.domain.Teacher

at org.apache.ibatis.exceptions.ExceptionFactory.wrapException(ExceptionFactory.java:23)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:104)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:95)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:59)
at com.mybatis.oneToone.App.main(App.java:17)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)

Caused by: org.apache.ibatis.builder.IncompleteElementException: Could not find result map com.mybatis.oneToone.domain.Teacher

at org.apache.ibatis.builder.MapperBuilderAssistant.setStatementResultMap(MapperBuilderAssistant.java:354)
at org.apache.ibatis.builder.MapperBuilderAssistant.addMappedStatement(MapperBuilderAssistant.java:292)
at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:113)
at org.apache.ibatis.session.Configuration.buildAllStatements(Configuration.java:579)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:505)
at org.apache.ibatis.session.Configuration.getMappedStatement(Configuration.java:500)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:100)
... 8 more

Caused by: java.lang.IllegalArgumentException: Result Maps collection does not contain value for com.mybatis.oneToone.domain.Teacher

at org.apache.ibatis.session.Configuration$StrictMap.get(Configuration.java:672)
at org.apache.ibatis.session.Configuration.getResultMap(Configuration.java:434)
at org.apache.ibatis.builder.MapperBuilderAssistant.setStatementResultMap(MapperBuilderAssistant.java:352)
... 14 more

希望好心人帮忙一下，我已经尽力排查我自己能够知道的错误，但是真的不米昂白为何还是报错。