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    <p>using the link <a href="http://blogs.msdn.com/b/mitsu/archive/2007/12/22/playing-with-linq-grouping-groupbymany.aspx" rel="nofollow noreferrer">Playing with Linq grouping: GroupByMany ?</a> suggested in <a href="https://stackoverflow.com/questions/2230202/how-can-i-hierarchically-group-data-using-linq">How can I hierarchically group data using LINQ?</a></p> <p>I first refactored my code into </p> <p><strong>Solution 1</strong></p> <pre><code>var results = from allPosts in db.Posts.OrderBy(p =&gt; p.DateCreated) group allPosts by allPosts.DateCreated.Year into postsByYear select new { postsByYear.Key, SubGroups = from yearLevelPosts in postsByYear group yearLevelPosts by yearLevelPosts.DateCreated.Month into postsByMonth select new { postsByMonth.Key, SubGroups = from monthLevelPosts in postsByMonth group monthLevelPosts by monthLevelPosts.Title into post select post } }; foreach (var yearPosts in results) { //create "year-level" item var year = new BlogEntry { Name = yearPosts.Key.ToString().ToLink(string.Empty) }; entries.Add(year); foreach (var monthPosts in yearPosts.SubGroups) { //create "month-level" item var month = new BlogEntry { Name = new DateTime(2000, (int)monthPosts.Key, 1).ToString("MMMM").ToLink(string.Empty), Parent = year }; year.Children.Add(month); foreach (var postEntry in monthPosts.SubGroups) { //create "blog entry level" item var post = postEntry.First() as Post; var blogEntry = new BlogEntry { Name = post.Title.ToLink("/Post/" + post.PostID + "/" + post.Title.ToSeoUrl()), Parent = month }; month.Children.Add(blogEntry); } } } </code></pre> <p>And then into a more generic</p> <p><strong>Solution 2</strong></p> <pre><code>var results = db.Posts.OrderBy(p =&gt; p.DateCreated).GroupByMany(p =&gt; p.DateCreated.Year, p =&gt; p.DateCreated.Month); foreach (var yearPosts in results) { //create "year-level" item var year = new BlogEntry { Name = yearPosts.Key.ToString().ToLink(string.Empty) }; entries.Add(year); foreach (var monthPosts in yearPosts.SubGroups) { //create "month-level" item var month = new BlogEntry { Name = new DateTime(2000, (int)monthPosts.Key, 1).ToString("MMMM").ToLink(string.Empty), Parent = year }; year.Children.Add(month); foreach (var postEntry in monthPosts.Items) { //create "blog entry level" item var post = postEntry as Post; var blogEntry = new BlogEntry { Name = post.Title.ToLink("/Post/" + post.PostID + "/" + post.Title.ToSeoUrl()), Parent = month }; month.Children.Add(blogEntry); } } } ................................................ public static class MyEnumerableExtensions { public static IEnumerable&lt;GroupResult&gt; GroupByMany&lt;TElement&gt;( this IEnumerable&lt;TElement&gt; elements, params Func&lt;TElement, object&gt;[] groupSelectors) { if (groupSelectors.Length &gt; 0) { var selector = groupSelectors.First(); //reduce the list recursively until zero var nextSelectors = groupSelectors.Skip(1).ToArray(); return elements.GroupBy(selector).Select( g =&gt; new GroupResult { Key = g.Key, Items = g, SubGroups = g.GroupByMany(nextSelectors) }); } else return null; } } public class GroupResult { public object Key { get; set; } public IEnumerable Items { get; set; } public IEnumerable&lt;GroupResult&gt; SubGroups { get; set; } } </code></pre>
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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