Entity Framework Constructor Error [duplicate]

Question

I have this segment of code selecting one column from a table which works fine:

db.Database.SqlQuery<string>("select Col1 from ....).ToList();

However, as expected when trying to select more than one column it errors as the result structure is incorrect.

I've tried the following:

db.Database.SqlQuery<Tuple<string, string>>("select Col1, Col2 from ...).ToList();

Which returns the error:

The result type 'System.Tuple`2[System.String,System.String]' may not be abstract and must include a default constructor.

How can I fix this, Am I correct to be using Tuple?

Answer 1

Define a class for your query result e.g.

class QueryResult
{
    public string Col1 { get; set; }
    public string Col2 { get; set; }
}

and query like this:

db.Database.SqlQuery<QueryResult>("select Col1, Col2 from ...).ToList();

Answer 2

You need to have a class that contains properties that have the same name of your columns in order for Database.SqlQuery to work. See here.

public class MyType
{
    public string Col1 { get; set; }
    public string Col2 { get; set; }
}

List<MyType> list = db.Database.SqlQuery<MyType>("select Col1, Col2 from ....").ToList();