SpringBoot整合TKMyBatis实现单表增删改查操作

    <dependency>
      <groupId>tk.mybatis</groupId>
      <artifactId>mapper-spring-boot-starter</artifactId>
      <version>2.1.5</version>
    </dependency>

@Setter
@Getter
@Table(name = "user")
public class User {
    /**
     * 用户ID
     */
    @Id
    private String id;
    /**
     * 用户姓名
     */
    private String userName;
    /**
     * 用户密码
     */
    private String passWord;
    /**
     * 年龄
     */
    private Integer age;
    /**
     * 性别
     */
    private String gender;
}

@Mapper
public interface UserMapper extends Mapper<User>, MySqlMapper {
}

@Service
public class UserService {
    @Resource
    private UserMapper userMapper;
    /**
     *  根据主键字段进行查询，方法参数必须包含完整的主键属性，查询条件使用等号
     */
    public User selectUserById(String userId){
        return userMapper.selectByPrimaryKey(userId);
    }
    /**
     *  查询全部结果
     */
    public List<User> selectAll(){
        return userMapper.selectAll();
    }
    /**
     *  根据实体中的属性值进行查询，查询条件使用等号
     */
    public List<User> selectByUserName(String userName){
        User user = new User();
        user.setUserName(userName);
        return userMapper.select(user);
    }
    /**
     *  根据实体中的属性进行查询，只能有一个返回值，有多个结果是抛出异常，查询条件使用等号。
     *  但是如果存在某个属性为int，则会初始化为0。可能影响到实际使用
     */
    public User selectOneByUserName(String userName){
        User user = new User();
        user.setUserName(userName);
        return userMapper.selectOne(user);

    }
    /**
     *  根据实体中的属性查询总数，查询条件使用等号
     */
    public Integer selectUserCount(String userName){
        User user = new User();
        user.setUserName(userName);
        return userMapper.selectCount(user);
    }
    /**
     *  保存一个实体，null的属性也会保存，不会使用数据库默认值
     */
    public void addUser(String userName,String passWord,Integer age,String gender){
        User user = new User();
        user.setId(String.valueOf(UUID.randomUUID()));
        user.setUserName(userName);
        user.setAge(age);
        user.setGender(gender);
        user.setPassWord(passWord);
        userMapper.insert(user);
    }
    /**
     *  保存一个实体，忽略空值，即没提交的值会使用使用数据库默认值
     */
    public void addUserService(String userName,String passWord){
        User user = new User();
        user.setId(String.valueOf(UUID.randomUUID()));
        user.setUserName(userName);
        user.setPassWord(passWord);
        userMapper.insertSelective(user);
    }
    /**
     *  根据主键字段进行删除，方法参数必须包含完整的主键属性
     */
    public void deleteById(String userId){
        userMapper.deleteByPrimaryKey(userId);
    }
    /**
     *  根据实体属性作为条件进行删除，查询条件使用等号
     */
    public void deleteByName(String userName){
        User user = new User();
        user.setUserName(userName);
        userMapper.delete(user);
    }
    /**
     *  根据主键更新实体全部字段，null值会被更新
     */
    public void updateById(String userId,String userName){
        User user = new User();
        user.setId(userId);
        user.setUserName(userName);
        userMapper.updateByPrimaryKey(user);
    }
    /**
     *  根据主键更新属性不为null的值
     */
    public void updateByIdSelective(String userId,String userName){
        User user = new User();
        user.setId(userId);
        user.setUserName(userName);
        userMapper.updateByPrimaryKeySelective(user);
    }    
}

@Mapper
public interface UserMapper extends Mapper<User>, SelectByIdsMapper, DeleteByIdsMapper {
}

     /**
     *  批量查询
     */
    public List<User> selectUserById(List<String> userIds){
        StringJoiner stringJoiner = new StringJoiner(",");
        for (String userId : userIds) {
            stringJoiner.add(userId);
        }
        return userMapper.selectByIds(stringJoiner.toString());
    }
    /**
     *  根据ID批量删除
     */
    public void deleteById(List<String> userIds){
        StringJoiner stringJoiner = new StringJoiner(",");
        for (String userId : userIds) {
            stringJoiner.add(userId);
        }
        userMapper.deleteByIds(stringJoiner.toString());
    } 

@Mapper
public interface UserMapper extends Mapper<User>, MySqlMapper, SelectByIdsMapper, DeleteByIdsMapper {
}

    /**
     *  批量添加
     */
    public void batchAdd(){
       List<User> list = new ArrayList();
        for (int i = 1; i < 6; i++) {
            User user = new User();
            user.setId(String.valueOf(i));
            user.setUserName("zs");
        }
        userMapper.insertList(list);
    }

Example example = new Example(User.class);
Example.Criteria criteria = example.createCriteria();

    public List<User> getUserByExample(String userName,String age){
        Example example = new Example(User.class);
        //Example.Criteria criteria = example.and();  
        //criteria.andEqualTo("age",age)  这里直接简写了
        example.and().andEqualTo("age",age)
                .andLike("userName",'%' +userName + '%');
        List<User> users = userMapper.selectByExample(example);
        return users;
    }