var scoreQuery = from student in students
                         from score in student.Scores
                            where score > 90
                            select new { Last = student.LastName, score };

This is the equivalent of:

SomeDupCollection<string, decimal> nameScore = new SomeDupCollection<string, float>();
foreach(Student curStudent in students)
{
   foreach(Score curScore in curStudent.scores)
   {
      if (curScore > 90)
      {
         nameScore.Add(curStudent.LastName, curScore);
      }
   }
}

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context.Log = Console.Out;

DataClassesDataContext context = new DataClassesDataContext();
IEnumerable<Order> result = context.Orders;
var product = result.Where(x => x.OrderID == 12);
context.Log = Console.Out;

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Power Tools

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Convert it to IEnumerable<T>

IEnumerable<string> canBeQueried = nvc.OfType<string>();

// To convert it to a string array  

string[] myArr = canBeQueried.Cast<String>().ToArray();

Convert it to IQueryable<T>

IQueryable queryable = nvc.AsQueryable();

Summary – Once you have these converted to either an IQueryable or an IEnumerable, you can execute your normal LINQ queries against them.

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There were a few confusing steps in setting up the tool.

1. Basically, it needs to have a datasource set up. It needs  this in the form of an ado.net connection string (the same string you would use in an app.config or a web.config file).  Setting up the datasource was a bit tricky – since it insisted on generating DBML files before it would accept the ado.net datasource. Once you provide it with a path to place the dbml file – it happily configures the datasource for use.
2. Linqer will generate the DBML (LinqtoSQL mapping files) for you.
3. Now, you are ready to INPUT your sql statements – and see their equivalent LINQ statements as the output (as shown below).

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First,  I got the commonly encountered multiple web.configs error (Error 3)

Error 3 It is an error to use a section registered as allowDefinition=’MachineToApplication’ beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.
Workaround – For some reason, web.config gets copied into subfolders – Find and delete all subfolders web.configs.

Next, I encountered  EF mapping errors – Mapping of CLR type to EDM type is ambiguous

Workaround – Make sure you update nuget packages (get EF framework) and regenerate the EDMX  .

On compilation, I encountered : Type or namespace objects could not be found

Workaround – Make sure you add a reference to System.data.entity.

Summary

Am sure I am missing a list of other common errors encountered in starting out with an existing EF codebase, but these are the ones I ran into.

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1. As all EDMX files are representations (abstractions) of some relational database, they belong in the Models folder.
2. The one exception would be file based datasources (mda files, excel files, SQL CE mdf files…) – which could be placed in the App_Data folder.

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