select
UserDao
中添加对应方法:/**
* @param name 用户名
* @return 对应用户名的用户对象
* @description 根据用户名获取用户
* @date 2020/7/14 14:52
* @author cunyu1943
* @version 1.0
*/
User getUserByName(String name);
/**
* @param password 密码
* @return 对应密码的用户对象
* @description 根据用户密码获取用户对象
* @date 2020/7/14 14:57
* @author cunyu1943
* @version 1.0
*/
User getUserByPassword(String password);
UserMapper.xml
中添加 Select
语句。其中各属性含义如下:<select id="getUserById" resultType="com.cunyu.pojo.User">
select * from user where id=#{id}
</select>
<select id="getUserByName" resultType="com.cunyu.pojo.User">
select * from user where name=#{name}
</select>
<select id="getUserByPassword" resultType="com.cunyu.pojo.User">
select * from user where password=#{password}
</select>
@Test
public void testGetUserById() {
// 执行 SQL 语句
UserDao mapper = sqlSession.getMapper(UserDao.class);
User user = mapper.getUserById(2);
System.out.println(user);
// 关闭 SqlSession
sqlSession.close();
}
@Test
public void testGetUserByName() {
UserDao mapper = sqlSession.getMapper(UserDao.class);
User user = mapper.getUserByName("村雨遥");
System.out.println(user);
sqlSession.close();
}
@Test
public void testGetUserByPassword(){
UserDao mapper = sqlSession.getMapper(UserDao.class);
User user=mapper.getUserByPassword("123456");
System.out.println(user);
sqlSession.close();
}
insert
UserDao
接口中添加对应方法 /**
* @description 添加用户
* @param user 待添加的用户对象
* @return
* @date 2020/7/14 15:50
* @author cunyu1943
* @version 1.0
*/
int addUser(User user);
UserMapper.xml
中添加 Insert
语句;<insert id="addUser" parameterType="com.cunyu.pojo.User">
insert into user(id, name, password) values (#{id},#{name},#{password})
</insert>
@Test
public void testAddUser() {
UserDao mapper = sqlSession.getMapper(UserDao.class);
User user = new User(5, "小雨", "6543210");
int i = mapper.addUser(user);
System.out.println(i);
// 提交事务到数据库
sqlSession.commit();
System.out.println("添加用户成功");
sqlSession.close();
}
update
UserDao
添加对应接口;/**
* @description 根据 id 修改用户
* @param user 待修改的用户对象
* @return
* @date 2020/7/14 16:04
* @author cunyu1943
* @version 1.0
*/
int updateUser(User user);
UserMapper.xml
中添加 update
语句;<update id="updateUser" parameterType="com.cunyu.pojo.User">
update user set name=#{name},password=#{password} where id=#{id}
</update>
@Test
public void testUpdateUser(){
// 获取 SqlSession 对象
SqlSession sqlSession = MybatisUtils.getSqlSession();
UserDao mapper = sqlSession.getMapper(UserDao.class);
User user = mapper.getUserById(1);
user.setPassword("7891011");
int i = mapper.updateUser(user);
sqlSession.commit();
System.out.println("更新数据成功");
sqlSession.close();
}
delete
userDao
中添加接口;/**
* @description 删除用户
* @param user 待删除的用户
* @return
* @date 2020/7/14 16:21
* @author cunyu1943
* @version 1.0
*/
int deleteUserById(User user);
UserMapper.xml
中添加 delete
语句;<delete id="deleteUserById" parameterType="com.cunyu.pojo.User">
delete from user where id=#{id}
</delete>
@Test
public void testDeleteUser(){
// 获取 SqlSession 对象
SqlSession sqlSession = MybatisUtils.getSqlSession();
UserDao mapper = sqlSession.getMapper(UserDao.class);
User user = mapper.getUserById(5);
int i = mapper.deleteUserById(user);
sqlSession.commit();
System.out.println("删除数据成功");
sqlSession.close();
}