HBSQLiteContext
eg:
HBFileItem *fileItem = [[MMFileItem alloc]init];
fileItem.file_md5 = @"123";
/// 新增
[fileItem save];
/// 删除
[fileItem delete];
/// 更新
[fileItem update];
/// 查找
MMFileItem fileItem = [[MMFileItem alloc]init];
fileItem.file_id = @"222";
fileItem = [fileItem findByModel];