MyBatis之传入参数

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

[html] view plain copy

1. <selectid="selectTeacher"parameterType="int"resultType="com.myapp.domain.Teacher">
2. select*fromTeacherwherec_id=#{id}
3. </select>

java代码

[java] view plain copy

1. List<Teacher>tList=teacherMapper.selectTeacher(2);
2. for(TeacherentityTemp:tList){
3. System.out.println(entityTemp.toString());
4. }

• JAVA实体类型参数示例：

[html] view plain copy

1. <selectid="selectTeacher"parameterType="com.myapp.domain.Teacher"resultType="com.myapp.domain.Teacher">
2. select*fromTeacherwherec_id=#{id}
3. </select>

[java] view plain copy

1. java代码
3. TeacherqueryTeacher=newTeacher();
4. queryTeacher.setId(2);
5. List<Teacher>tList=teacherMapper.selectTeacher(queryTeacher);
6. for(TeacherentityTemp:tList){
7. System.out.println(entityTemp.toString());}

• Map参数示例：
  
  [html] view plain copy

  1. <selectid="selectTeacher"parameterType="Map"resultType="com.myapp.domain.Teacher">
  2. select*fromTeacherwherec_id=#{id}andsex=#{sex}
  3. </select>
  
  
  [java] view plain copy

  1. java代码
  3. Map<String,String>map=newHasMap<String,String>();
  4. map.put("id","2");
  5. map.put("sex","男");
  6. List<Teacher>tList=teacherMapper.selectTeacher(map);
  7. for(TeacherentityTemp:tList){
  8. 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

[java] view plain copy

1. publicList<Teacher>selectTeacher(@Param(value="id")Stringid,@Param(value="sex")Stringsex);

XML文件

[html] view plain copy

1. <selectid="selectTeacher"resultType="com.myapp.domain.Teacher">
2. select*fromTeacherwherec_id=#{id}andsex=#{sex}
3. </select>

测试代码

[java] view plain copy

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

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

[html] view plain copy

1. <selectid="selectTeacher"parameterType="int"resultType="com.myapp.domain.Teacher">
2. select*fromTeacherwherec_id=#{id}
3. </select>

java代码

[java] view plain copy

1. List<Teacher>tList=teacherMapper.selectTeacher(2);
2. for(TeacherentityTemp:tList){
3. System.out.println(entityTemp.toString());
4. }

• JAVA实体类型参数示例：

[html] view plain copy

1. <selectid="selectTeacher"parameterType="com.myapp.domain.Teacher"resultType="com.myapp.domain.Teacher">
2. select*fromTeacherwherec_id=#{id}
3. </select>

[java] view plain copy

1. java代码
3. TeacherqueryTeacher=newTeacher();
4. queryTeacher.setId(2);
5. List<Teacher>tList=teacherMapper.selectTeacher(queryTeacher);
6. for(TeacherentityTemp:tList){
7. System.out.println(entityTemp.toString());}

• Map参数示例：
  
  [html] view plain copy

  1. <selectid="selectTeacher"parameterType="Map"resultType="com.myapp.domain.Teacher">
  2. select*fromTeacherwherec_id=#{id}andsex=#{sex}
  3. </select>
  
  
  [java] view plain copy

  1. java代码
  3. Map<String,String>map=newHasMap<String,String>();
  4. map.put("id","2");
  5. map.put("sex","男");
  6. List<Teacher>tList=teacherMapper.selectTeacher(map);
  7. for(TeacherentityTemp:tList){
  8. 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

[java] view plain copy

1. publicList<Teacher>selectTeacher(@Param(value="id")Stringid,@Param(value="sex")Stringsex);

XML文件

[html] view plain copy

1. <selectid="selectTeacher"resultType="com.myapp.domain.Teacher">
2. select*fromTeacherwherec_id=#{id}andsex=#{sex}
3. </select>

测试代码

[java] view plain copy

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