Databases
StackOverflow2013
Postsdbo
POMongoDB C# Driver: How do I ensure an index using LINQ expressions on the contents of an array?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POMongoDB C# Driver: How do I ensure an index using LINQ expressions on the contents of an array?
    primarykey
    data
    text
    <p>How can I ensure an index using LINQ expressions on the contents of an array using the MongoDB C# driver?</p> <p>I currently have a domain object that looks roughly like this:</p> <pre><code>public class Team { public Team() { Members = new List&lt;LazyReference&gt;(); } public MongoDB.Bson.ObjectId Id { get; set; } public string DisplayName { get; set; } public LazyReference Leader { get; set; } public List&lt;LazyReference&gt; Members { get; private set; } } public class LazyReference { public MongoDB.Bson.ObjectId Id { get; set; } } </code></pre> <p>On my collection, I have initialized a couple of indexes like this:</p> <pre><code>collection.EnsureIndex(IndexKeys&lt;Team&gt;.Ascending(t =&gt; t.DisplayName), IndexOptions.SetUnique(true)); collection.EnsureIndex(IndexKeys&lt;Team&gt;.Ascending(t =&gt; t.Leader.Id), IndexOptions.SetUnique(false)); </code></pre> <p>How can I do the same to ensure a fast index of the Members when looking up by Members[n].Id, where n is any of the members? I am aware that I can create an index as follows, but since this does not use the LINQ expressions, it is not safe for future renames of properties.</p> <pre><code>collection.EnsureIndex(new IndexKeysBuilder().Ascending("Members._id"), IndexOptions.SetUnique(false)); </code></pre> <p>I have also tried the following, but it only indexes the index specified:</p> <pre><code>collection.EnsureIndex(IndexKeys&lt;Team&gt;.Ascending(t =&gt; t.Members[0].Id), IndexOptions.SetUnique(false)); </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USMatt DeKrey
    1. USMatt DeKrey
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. COIs `LazyReference` your own class? Could you post its code or describe its purpose?
      singulars
      1. POMongoDB C# Driver: How do I ensure an index using LINQ expressions on the contents of an array?
      1. USZaid Masud
    2. CO@ZaidMasud, I've updated to include a basic declaration of LazyReference. Ultimately, what I've provided is all that is relevant to this example, since the rest are methods and non-persisted properties.
      singulars
      1. POMongoDB C# Driver: How do I ensure an index using LINQ expressions on the contents of an array?
      1. USMatt DeKrey
 

Querying!

 
Guidance
A row detail

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.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload