mybatis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>

  
  

   java代码
  
   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>

测试代码

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