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POEntityFramework Code First approach for mapping convoluted legacy database linking table?
 

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  1. POEntityFramework Code First approach for mapping convoluted legacy database linking table?
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    <p>I am working with a legacy database that cannot have its structure changed (at least not yet), and it has something like this:</p> <pre><code>**Profile**: profile_id first_name last_name **OneBigLookupTableToRuleThemAll**: lookup_id (PK) category_id (PK) (refers to a recrod in a OneBigCategoryTableToRuleThemAll) description (basically a label) **ProfileProperties**: property_key (PK GUID) profile_id lookup_id UNIQUE constraint on profile_id, lookup_id </code></pre> <p>As an example of two categories:</p> <pre><code>Degrees (MD, PhD, MS, MPH, etc) -- cat_id 1, for example Job Responsibilities (Statistician, Medical Doctor, Epidemiologist, etc) -- cat_id 2 </code></pre> <p>So, in the Lookup table, we end up with stuff like this:</p> <pre><code>lookup_id, cat_id, description 1 , 1 , MD 2 , 1 , PhD 3 , 1 , MS 4 , 1 , MPH 5 , 2 , Statistician 6 , 2 , Medical Doctor 7 , 2 , Epidemiologist </code></pre> <p>Thus, in the ProfileProperties table we end up with stuff like:</p> <pre><code>property_key, profile_id, lookup_id some guid , 1 , 1 -- MD degree some guid , 1 , 4 -- MPH degree some guid , 1 , 6 -- Medical Doctor </code></pre> <p>I would like to have an entity like this:</p> <pre><code>public class Profile { public int ProfileId { get; } public string FirstName { get; set; } public string LastName { get; set; } public ICollection&lt;JobResponsibility&gt; JobResponsibilities { get; set; } public ICollection&lt;Degree&gt; Degrees { get; set; } } public class JobResponsibility { public int Id { get; set; } public string Description { get; set; } } public class Degree { public int Id { get; set; } public string Description { get; set; } } </code></pre> <p>-- Actually, in the setters of the Id, I would like to constrain the value to one of the actual values that is in the database, though I'm not sure I'd go to full blown Enum-type support (and I know code first does not support that yet)</p> <p>I believe one of the EntityFramework mapping scenarios should be able to handle this, but I'm having trouble figuring out what I need to do to get this to work.</p> <p>Anyone have any tips or resources I can read up on this kind of scenario? I'm thinking it's actually going to end up very basic, but I'm new to EF.</p> <p>Thank you, Josh</p>
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