一、模糊查询

 /*** 通过用户名模糊查询用户信息* @param mohu* @return*/List<User> getUserByLike(@Param("mohu") String mohu);

<!--List<User> getUserByLike(@Param("mohu") String mohu);--><select id="getUserByLike" resultType="com.itheima.mybatis.pojo.User">select * from tb_user where username like '%${mohu}%';</select>

@Testpublic void testGetUserByLike(){SqlSession sqlSession = SqlSessionUtils.getSqlSession();SpecialSQLMapper mapper = sqlSession.getMapper(SpecialSQLMapper.class);List<User> list = mapper.getUserByLike("a");list.forEach(System.out::println);

二、批量删除

 /*** 批量删除* @param ids*/void deleteMoreUser(@Param("ids") String ids);```
```xml
<!--void deleteMoreUser(@Param("ids") String ids);;--><delete id="deleteMoreUser">delete from tb_user where id in ${ids};</delete>

    /*** 批量删除*/@Testpublic void testDeleteMoreUser() {SqlSession sqlSession = SqlSessionUtils.getSqlSession();SpecialSQLMapper mapper = sqlSession.getMapper(SpecialSQLMapper.class);mapper.deleteMoreUser("9,10");}

三、动态设置表名

/***动态设置表名，查询用户信息* @param tableName* @return*/List<User> getUserList(@Param("tableName") String tableName);

    <!--List<User> getUserList(String tableName);--><select id="getUserList" resultType="User">select * from ${tableName};</select>

    /*** 动态设置表名，查询用户信息*/@Testpublic void testGetUserList() {SqlSession sqlSession = SqlSessionUtils.getSqlSession();SpecialSQLMapper mapper = sqlSession.getMapper(SpecialSQLMapper.class);List<User> list = mapper.getUserList("tb_user");list.forEach(System.out::println);}

四、添加功能获取自增的主键

场景模拟：
t_clazz(clazz_id,clazz_name)
t_student(student_id,student_name,clazz_id)
1、添加班级信息
2、获取新添加的班级的id
3、为班级分配学生，即将某学的班级id修改为新添加的班级的id

/*** 添加用户信息* @param user* @return* useGeneratedKeys：设置使用自增的主键* keyProperty：因为增删改有统一的返回值是受影响的行数，因此只能将获取的自增的主键放在传输的参 
数user对象的某个属性中*/
int insertUser(User user);

<!--int insertUser(User user);-->
<insert id="insertUser" useGeneratedKeys="true" keyProperty="id">insert into t_user values(null,#{username},#{password},#{age},#{sex})
</insert>

public void testJDBC(){try {Class.forName("");Connection connection = DriverManager.getConnection("","","");String sql = "insert into tb_user values()";PreparedStatement ps = connection.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);ps.executeUpdate();ResultSet resultSet = ps.getGeneratedKeys();resultSet.next();resultSet.getInt(1);} catch (Exception e) {e.printStackTrace();}