在MyBatis中,mapper接口用于定義數(shù)據(jù)操作的方法,而對(duì)應(yīng)的Mapper XML文件用于配置SQL語(yǔ)句和映射關(guān)系。下面是使用mapper的一般步驟:
1. 創(chuàng)建Mapper接口:在接口中定義數(shù)據(jù)操作的方法,例如:
```java
public interface UserMapper {
User getUserById(int id);
void insertUser(User user);
void updateUser(User user);
void deleteUser(int id);
}
```
2. 創(chuàng)建對(duì)應(yīng)的Mapper XML文件:在XML文件中配置SQL語(yǔ)句和映射關(guān)系,例如:
```xml
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
SELECT * FROM users WHERE id = #{id}
INSERT INTO users (id, name, age) VALUES (#{id}, #{name}, #{age})
UPDATE users SET name = #{name}, age = #{age} WHERE id = #{id}
DELETE FROM users WHERE id = #{id}
```
3. 配置MyBatis的配置文件:在配置文件中配置數(shù)據(jù)源、mapper掃描路徑等信息,例如:
```xml
```
4. 使用Mapper接口:在代碼中通過(guò)Mybatis的SqlSessionFactory獲取Mapper接口的實(shí)例,然后調(diào)用方法進(jìn)行數(shù)據(jù)操作,例如:
```java
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
SqlSession sqlSession = sqlSessionFactory.openSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User user = userMapper.getUserById(1);
user.setName("New Name");
userMapper.updateUser(user);
sqlSession.commit();
sqlSession.close();
```
以上就是使用Mybatis中的mapper的一般步驟,希望對(duì)你有所幫助。