多对多和Linq:更新关系

所以我有三个表(好的,两个表和一个映射表),如下所示:

dbo.Catalog
    CatalogID // int [not null] autoincrement PK
dbo.Product
    ProductID // int [not null] autoincrement PK
dbo.CatalogProductMap
    CatalogID // int [not null] PK
    ProductID // int [not null] PK

我在页面上有用于更新的复选框 Product 就像这样:

<% foreach(var catalog in dataContext.Catalogs){ %>
    <!-- add a checkbox for each catalog  -->
    <input type="checkbox" name="catalog[<%= catalog.CatalogID %>]" />
<% } %>

在我处理帖子的代码中,我有:

 // Regex to check Form keys and group each ID
 var rCatalog = new Regex("^catalog\\[(\\d+)\\]$");
 // gets all "checked" CatalogIDs POSTed
 IEnumerable<int> checkedCatalogs =
            Request.Form.AllKeys
                   // get only the matching keys...
                   .Where(k => rCatalog.IsMatch(k))
                   // and select the ID portion of those keys...
                   .Select(c => int.Parse(rCatalog.Match(c).Groups[1].Value));

然后这个臭的部分:

更新!

多亏了 Dave Swersky 对于 Any<> 方法

Product Product = getProductBeingUpdated();

// iterate through each EXISTING relationship for this product
// and REMOVE it if necessary.
myDataContext.CatalogProductMaps
    .DeleteAllOnSubmit(from map in Product.CatalogProductMaps
        where !checkCatalogs.Contains(map.CatalogID)
        select map);

// iterate through each UPDATED relationship for this product
// and ADD it if necessary.
Product.CatalogProductMaps
    .AddRange(from catalogID in checkedCatalogs
        where !Product.CatalogProductMaps.Any(m => m.CatalogID == catalogID)
        select new Group{
            CatalogID = catalogID
    });


myDataContect.SubmitChanges();

所以我的问题是:

这不可能是 正确的 完成我正在做的事情的方法。如何改进可维护性(和效率)代码?