在LINQ查询模型值使用列表 [英] Using list in a model value in LINQ query
问题描述
我在asp.net MVC开发的非常基本的阶段。所以有时候我用简单的LINQ查询工作奋斗。
I am at very basic stage of asp.net MVC development. So sometimes I struggle with simple LINQ queries to work.
场景 -
我有一个网页，有一些图片键，用户在该影像注释（就像从用户的含评论Facebook的一个职位）。
I have A page that has some Image and comment on that Image by users (Just Like a post on facebook containing comments from users).
所以我保存来自textarea的这些意见，并通过Ajax查询发送图片ID。
So I am saving those comments from the textarea and sending Image ID via Ajax query.
这是我的控制器的操作方法 -
保存评论 -
[HttpPost]
public void SaveComment(CardModel card) {
CardCommentTable commenttable = new CardCommentTable();
commenttable.CardComment = card.cardComment;
commenttable.FKcardID = card.cardID;
db.CardCommentTables.InsertOnSubmit(commenttable);
db.SubmitChanges();
}
此注释保存在 CardCommentTable 有在图像表的外键引用被保存。
This Comment is saved in CardCommentTable that has foreign key reference of Table in that Image is saved.
视图页面上渲染图像等领域 -
这使得查询图像等领域，使得它的图像后。像标题， dateofsubmit ，像等。
This query renders Image and other fields that make it An Image post. Like title, dateofsubmit, Like etc.
public ActionResult CardDetails(CardModel card) {
var cardDetail = (from u in db.CardTables
where u.CardID == card.cardID
select new CardModel {
cardID = u.CardID,
cardHashCode = u.CardHashCode,
cardDate = u.CardDate,
cardFileName = u.CardFileName,
cardFilePath = u.CardFilePath,
cardTitle = u.CardTitle
}).ToList();
return View(cardDetail);
}
现在在 cardTable 我有一个名为 cardComment 在我想告诉所有的那些保存的评论多了一个列表 CardCommentTable 。
Now In cardTable I have one more column named cardComment in that I want to show all those saved comments from table CardCommentTable.
所以，我想 -
public ActionResult CardDetails(CardModel card) {
var allsavedcomments= (from u in db.CardCommentTables
where u.FKcardID == card.cardID
select u).ToList();
var cardDetail = (from u in db.CardTables
where u.CardID == card.cardID
select new CardModel {
cardID = u.CardID,
cardHashCode = u.CardHashCode,
cardDate = u.CardDate,
cardFileName = u.CardFileName,
cardFilePath = u.CardFilePath,
cardTitle = u.CardTitle,
cardComment = allsavedcomments // Trying to render all saved coments here.
}).ToList();
return View(cardDetail);
}
查看 -
@model IEnumerable<FunRanger.Models.CardModel>
@foreach (var item in Model) {
<script type="text/javascript">
$(function () {
$('#save-comment').click(function () {
var textareavalue = $('#textarea-comment').val();
$.ajax({
url: '/Home/SaveComment/',
type: 'post',
data: '&cardComment=' + textareavalue + '&cardID=' + '@item.cardID',
success: function (data) {
$('#all-comments').append(data);
}
});
});
});
</script>
using (Html.BeginForm()) {
@Html.ValidationSummary(true)
@if (Model != null) {
<h2 class="header-wrapmain">
@item.cardTitle
</h2>
@item.cardDate.ToShortDateString()
<img src="@item.cardFilePath" />
<a href="#" class="@item.cardHashCode" rel="tooltip" data-placement="bottom" title="Filter by @item.cardHashCode">
#@item.cardHashCode</a>
}
else {
<div class="alert alert-danger">
No More items to preview
</div>
}
}
<textarea class="span12" rows="5" id="textarea-comment" style="resize: none" placeholder="Enter a comment..."></textarea>
<a href="javascript:;" id="save-comment" class="btn-primary btn">Save comment</a>
<ol>
<li>
@item.cardComment
</li>
</ol>
}
我怎样才能插入列表结果在这里的一列。
我如何证明这个上面的查询所有已保存的意见？
How do I show all saved comments with this above query?
感谢您的帮助。
推荐答案
我稍微装修你的code。与外键关系船。这将节省您的使用两个不同的查询到你的数据库（如你现在在做什么）。
I slightly renovated your code with Foreign key relations ship. This will save your from using two different queries to your database (like what you are doing now).
所以，如果你数据库模型是这样的 -
So if you Database Model looks like this -
然后，你应该有一个视图模型在以这种方式code -
Then you should have one viewmodel in your code in this way -
public class ImageViewModel
{
public string ImageId { get; set; }
public string ImageUrl { get; set; }
public List<string> Comments { get; set; }
}
和控制器的动作将返回所有的结果应该是这样的 -
And your controller action which will return all the results should be like this -
public class ListController : Controller
{
public ActionResult Index()
{
ImageViewModel model;
using (SampleEntities entities = new SampleEntities())
{
model = (from p in entities.Images
where p.ImageId == "1"
select new ImageViewModel()
{
ImageId = p.ImageId,
ImageUrl = p.ImageUrl,
Comments = p.ImageComments.Select(pa => pa.Comment).ToList()
}).FirstOrDefault();
}
return View(model);
}
}
最后，将显示所有图片搜索结果的看法 -
Finally the view which will display all the Image results -
@model MVC.Controllers.ImageViewModel
@{
ViewBag.Title = "Index";
}
<h2>Index</h2>
<div>
<h4>ImageViewModel</h4>
<hr />
<dl class="dl-horizontal">
<dt>
@Html.DisplayNameFor(model => model.ImageId)
</dt>
<dd>
@Html.DisplayFor(model => model.ImageId)
</dd>
<dt>
@Html.DisplayNameFor(model => model.ImageUrl)
</dt>
<dd>
@Html.DisplayFor(model => model.ImageUrl)
</dd>
<br/>
@foreach (var item in Model.Comments)
{
@item <br/>
}
</dl>
</div>
输出会 -
这篇关于在LINQ查询模型值使用列表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
