MyBatis之传入参数

在MyBatis的select、insert、update、delete这些元素中都提到了parameterType这个属性。MyBatis现在可以使用的parameterType有基本数据类型和JAVA复杂数据类型

• 基本数据类型：包含int,String,Date等。基本数据类型作为传参，只能传入一个。通过#{参数名} 即可获取传入的值
• 复杂数据类型：包含JAVA实体类、Map。通过#{属性名}或#{map的KeyName}即可获取传入的值

 

• 基本数据类型参数示例：

根据班级ID查询教师列表

xml文件

  

  <select id="selectTeacher" parameterType="int" resultType="com.myapp.domain.Teacher">
  	select * from Teacher where c_id=#{id}
  </select>

java代码

 

List<Teacher> tList = teacherMapper.selectTeacher(2);    
for (Teacher entityTemp : tList) {    
    System.out.println(entityTemp.toString());    
} 

• JAVA实体类型参数示例：
•  

  <select id="selectTeacher" parameterType="com.myapp.domain.Teacher" resultType="com.myapp.domain.Teacher">  
      select * from Teacher where c_id=#{id}  
  </select> 

  java代码  
    
  Teacher queryTeacher=new Teacher();  
  queryTeacher.setId(2);  
  List<Teacher> tList = teacherMapper.selectTeacher(queryTeacher);    
  for (Teacher entityTemp : tList) {    
      System.out.println(entityTemp.toString()); } 
  
  
  
  
  

• Map参数示例：

• <select id="selectTeacher" parameterType="Map" resultType="com.myapp.domain.Teacher">  
      select * from Teacher where c_id=#{id} and sex=#{sex}  
  </select> 

  
  
  

  Map<String,String> map=new HasMap<String,String>();  
  map.put("id","2");  
  map.put("sex","男");  
  List<Teacher> tList = teacherMapper.selectTeacher(map);    
  for (Teacher entityTemp : tList) {    
      System.out.println(entityTemp.toString()); }  

  
  
  

 另外MyBatis还提供了一个使用注解来参入多个参数的方式。这种方式需要在接口的参数上添加@Param注解

示例：

接口方法

public List<Teacher> selectTeacher(@Param(value="id") String id,@Param(value="sex") String sex);  

XML文件

<select id="selectTeacher"  resultType="com.myapp.domain.Teacher">  
    select * from Teacher where c_id=#{id} and sex=#{sex}  
</select>  

  view plain cop

测试代码

List<Teacher> tList = teacherMapper.selectTeacher("2","男");    
for (Teacher entityTemp : tList) {    
    System.out.println(entityTemp.toString());