error 0040: The Type … is not qualified with a namespace or alias. Only PrimitiveTypes can be used without qualification.

This is caused by Npgsql mapping a very sparse selection of type-names to the underlying Entity Framework type structures.

As of 2.0.9, the following type names are recognized:

• bool
• int2
• int4
• float4
• float8
• uuid
• numeric
• bpchar
• varchar
• text
• xml
• timestamp
• date
• bytea

string[] sentences = new string[] {
  "The quick brown fox jumps over the lazy dog",
  "The quick brown fox jumps over the lazy cat"};
string[] findAnd = new string[] { "fox", "dog" };
string[] findOr = new string[] { "dog", "cat" };

The first part (find all) is simple:

var queryand = sentences.AsQueryable();
foreach (string find in findAnd)
{
  string f = find;
  queryand = queryand.Where(s => s.Contains(find));
}

Console.WriteLine(string.Join("\n", queryand.ToArray()));

But how to implement to Or part? Well, google is my best friend. I found the following solution:

Predicate Builder on C# 3.5 in a Nutshell

But this solution does not work with Entity Framework: Predicate Builder and Entity Framework on stackoverflow.com

After implementing this solution your code will look like this:

var predicate = Extensions.False<string>();
foreach (string find in findOr)
{
  string f = find;
  predicate = predicate.Or(s => s.Contains(f));
}
var queryor = sentences.AsQueryable().Where(predicate);
Console.WriteLine(string.Join("\n", queryor.ToArray()));

P.S.: You can find an ExpressionVisitor here: ExpressionVisitor at MSDN

But the nice small Debug Windows “Auto” and “Locals” ignore these attributes. So your debugger will continue to do unnecessary work – an amazing feature. This is especially bad since there is a timeout within the debugger’s evaluator which will kill the debugger to the point of unusability when hit.

And yes – this is by Design:

• First Microsoft Connect entry
• Second Microsoft Connect entry

But for another project I would like to use the designer. And I would like to use Complex Types. This is a situation where I dont like Entity Framework (or better: the Designer).

Error: ComplexType elements are not supported in the Entity Designer.

Yep – this is a known issue:

• Microsoft Connect Bug
• Microsoft Forum discussion

So I’ll try not to use Complex Types (with some bad tricks this sould be possible) or I will continue writing EDMX Files by hand…

What I tried in the EDMX File (or better: CSDL, MSL and SSDL):

CSDL:

<Association Name="FK_ParkingSpace_Employee">
          <End Role="Employee" Type="Database1Model.Employee" Multiplicity="0..1" />
          <End Role="ParkingSpace" Type="Database1Model.ParkingSpace" Multiplicity="0..1" />
</Association>

Same in the SSDL:

<Association Name="FK_ParkingSpace_Employee">
  <End Role="Employee" Type="Database1Model.Store.Employee" Multiplicity="0..1" />
  <End Role="ParkingSpace" Type="Database1Model.Store.ParkingSpace" Multiplicity="0..1" />
  <ReferentialConstraint>
    <Principal Role="Employee">
      <PropertyRef Name="ID" />
    </Principal>
    <Dependent Role="ParkingSpace">
      <PropertyRef Name="fk_Employee" />
    </Dependent>
  </ReferentialConstraint>
</Association>

But that gave me this Error:

Multiplicity is not valid in Role ‘ParkingSpace’ in relationship ‘FK_ParkingSpace_Employee’. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be *.

What? Why? OK, I didn’t understand and could not find any information on the web how to define a 1:1 Relation in Entity Framework. So I made a small test application. And the SSDL was:

<Association Name="FK_ParkingSpace_Employee">
  <End Role="Employee" Type="Database1Model.Store.Employee" Multiplicity="0..1" />
  <End Role="ParkingSpace" Type="Database1Model.Store.ParkingSpace" Multiplicity="*" />
  <ReferentialConstraint>
    <Principal Role="Employee">
      <PropertyRef Name="ID" />
    </Principal>
    <Dependent Role="ParkingSpace">
      <PropertyRef Name="fk_Employee" />
    </Dependent>
  </ReferentialConstraint>
</Association>

Multiplicity=”*”

Ah, OK – from the Database’s viewpoint there is no 1:1 Relation. There’s a 1:n Relation. So I have to define 1:n Relation in the SSDL too. A Constraint in the Database and in the Object Model ensures, that this 1:n Relation is a 1:1 Relation. Or am I wrong?

This is nasty because the EF will always try to load the Reference from the Database.

Or I made a mistake…

Here is an example:

[EdmRelationshipNavigationPropertyAttribute("Model", "FK_Auftrag_Mitarbeiter", "A_Mitarbeiter")]
public App.Mitarbeiter Mitarbeiter
{
  get
  {
    EntityReferenceMitarbeiter> r =
      ((IEntityWithRelationships)(this)).RelationshipManager
      .GetRelatedReferenceMitarbeiter>
      ("Model.FK_Auftrag_Mitarbeiter", "A_Mitarbeiter");

    if (!r.IsLoaded)
      r.Load();

    return r.Value;
  }
}

1. Embed your files as a resource in your DLL
2. In your app.config change the connectionstring from:

<add name="KistlContext"
  connectionString="metadata=.\Model.csdl|.\Model.ssdl|.\Model.msl;
  provider=System.Data.SqlClient;
  provider connection string='Data Source=.\SQLEXPRESS;
    Initial Catalog=YourDatabase;
    Integrated Security=True;
    MultipleActiveResultSets=true;'"
  providerName="System.Data.EntityClient" />

to:

<add name="KistlContext"
  connectionString="metadata=res://*;
  provider=System.Data.SqlClient;
  provider connection string='Data Source=.\SQLEXPRESS;
    Initial Catalog=YourDatabase;
    Integrated Security=True;
    MultipleActiveResultSets=true;'"
  providerName="System.Data.EntityClient" />

It does not matter in which assembly the model is embedded.