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POHow do I represent an option calculated column with EF Code First?
 

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  1. POHow do I represent an option calculated column with EF Code First?
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    <p>I have a situation where I have a table of entries that I'll be querying on, but in some cases I'll have additional information available.</p> <p>For instance, if I have a table of <code>people</code>, I want to be able to search by name, but I also want to store some coordinates and search based on their location, but also expose that distance in the object model. So, for instance, suppose my <code>people</code> table looks something like this:</p> <pre><code>PersonId int Name nvarchar(100) Address nvarchar(100) Latitude float(10,6) Longitude float(10,6) </code></pre> <p>And the entity class is defined like this:</p> <pre><code>public class Person { public int PersonId { get; set; } public sting Name { get; set; } public float Latitude { get; set; } public float Longitude { get; set; } } </code></pre> <p>Then I can easily find a person by name using: </p> <pre><code>var people = from p in myDb.People where p.Name.Contains("joe"); </code></pre> <p>Now, I have user-defined function called <code>CalculateDistance</code> that I've created to handle this distance calculations. And so my SQL will look something like this:</p> <pre><code>String sql = "SELECT *, dbo.CalculateDistance(" + location.X + ", " + location.Y + ", Latitude, Longitude) AS Distance FROM people ORDER BY Distance </code></pre> <p>How do I represent this in code? I've tried adding a property like this to the class:</p> <pre><code>public virtual float Distance { get; set; } </code></pre> <p>But then the name queries fail because there is no Distance column. I also tried extending the Person class:</p> <pre><code>public class PersonWithDistance: Person { public float Distance { get; set; } } </code></pre> <p>But that caused even more problems with the way the mappings are generated. </p> <p>What's the correct way to implement something like this? Do I have to create an entirely separate separate class for the results from the distance query?</p>
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