select master based on detail in LINQ
<p>I have ServiceRequest table, where it contains a field to specify to location (the branch), and the type of the Support(IT issue, fleet issue, Maintenance...)</p>

<pre><code>ServiceRequest: { srID(PK), srDetail, LocationID(FK), SupportID(FK), StatusID(FK), ServiceDate }
</code></pre>

<p>then I have Supervisor table, where it define the list of location, and the type of issues he's supervising:</p>

<pre><code>Supervisor: { UserID(FK), LocationID(FK), SupportID(FK) }
</code></pre>

<p><strong><em>what is the query that I can use</em></strong> so when a supervisor login, I want to show him all service requests that belong to the locations and the support types he covers.</p>

<p>currently, I am getting <strong>all</strong> (active) service requests using:</p>

<pre><code>short statusId = short.Parse(ddlStatus.Value);
return db.ServiceRequests.Where(sr =&gt; sr.StatusID == statusId)
         .OrderByDescending(s=&gt;s.ServiceDate).ToList();
</code></pre>