Question

我在项目中使用Servietack和OrmLite。发送请求（Db.Select）后，经过很长时间后，没有响应返回。

       public object Get(GetCategoryNews request)
        {
            var PageCount = 20;
            var skip = (request.Page.GetValueOrDefault(1) - 1) * PageCount;

            var cacheKey = UrnId.Create<GetCategoryNews>(DateTime.Now.ToString("yyMMddhhmm") + skip);
            return base.Request.ToOptimizedResultUsingCache(base.Cache, cacheKey, () =>
            {
            //On this line, waiting and no response
              var status = Db.Select<News>().Skip(skip).Take(PageCount).Select(o => new NewsResponse() {
                    Id = o.Id,
                    CreateOn = o.CreateOn,
                    Description = o.Description,
                    PublishOn = o.PubDate,
                    Title = o.Title
                });
                return status;
            });
        }

但是当Count请求时，它运作良好

    var count = Db.Count<News>();

我该如何解决这个问题？

Answer 1

调用Db.Select<News>()会返回List<News>，将整个表格结果下载到内存列表集合中。由于您正在尝试分页结果集，因此您需要构建一个SqlExpression，OrmLite执行该//Create SQL Query var q = db.From<News>() .Skip(skip) .Take(PageCount); var results = db.Select(q); //Executes paged query return results.Select(o => new NewsResponse { Id = o.Id, CreateOn = o.CreateOn, Description = o.Description, PublishOn = o.PubDate, Title = o.Title });仅返回您感兴趣的结果，例如：

OnInitialized

OrmLite db.Select不返回响应

1 个答案: