title: string.IsNullOrEmpty + Entity Framework 5
body: <p>It's been a while since I've used Entity Framework, and I'm jumping back in with EF 5, but wouldn't this query:</p>
  
  <pre><code>SELECT 
      c.OrganizationName as CompanyName,
      c.OrganizationKey as CompanyId,
      ISNULL(a.Line1, '') as Line1,
      ISNULL(a.Line2, '') as Line2,
      a._CityStateZip as CityStateZip
  FROM Organizations c
  JOIN Addresses a ON c.AddressKey = a.AddressKey
  WHERE c.OrganizationName LIKE @term + '%'
  AND c.IsSuspended = 0
  AND c.IsActive = 1
  </code></pre>
  
  <p>be the same as:</p>
  
  <pre><code>var results = (from c in adms.Organizations
                 where c.OrganizationName.StartsWith(term)
                 where !c.IsSuspended
                 where c.IsActive
                 select new
                 {
                   CompanyName = c.OrganizationName,
                   CompanyId = c.OrganizationKey,
                   Line1 = (string.IsNullOrEmpty(c.Address.Line1) ? string.Empty : c.Address.Line1),
                   Line2 = (string.IsNullOrEmpty(c.Address.Line2) ? string.Empty : c.Address.Line2),
                   CityStateZip = c.Address._CityStateZip
                 }).ToList();
  </code></pre>
  
  <p>When I run the LINQ to SQL code, I get the following error:</p>
  
  <pre><code>Could not translate expression 
  'Table(Organization).Where(c =&gt; c.OrganizationName
  .StartsWith(Invoke(value(System.Func`1[System.String]))))
  .Where(c =&gt; Not(c.IsSuspended))
  .Where(c =&gt; c.IsActive)
  .Select(c =&gt; new &lt;&gt;f__AnonymousType2`5(
  CompanyName = c.OrganizationName, 
  CompanyId = c.OrganizationKey, 
  Line1 = IIF(IsNullOrEmpty(c.Address.Line1), 
  Invoke(value(System.Func`1[System.String])), c.Address.Line1), 
  Line2 = IIF(IsNullOrEmpty(c.Address.Line2), 
  Invoke(value(System.Func`1[System.String])), c.Address.Line2), 
  CityStateZip = c.Address._CityStateZip))' 
  into SQL and could not treat it as a local expression.
  </code></pre>
  
  <p>Am I completely missing something here?  I thought I could use string.IsNullOrEmpty with LINQ to SQL.</p>