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POLinq-to-SQL Table Coalesce
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copied!<p>Let's say I have three tables:</p> <p>User</p> <pre> ID | Name =========== 1 | UserA ----------- 2 | UserB ----------- </pre> <p>Setting</p> <pre> ID | Name | Default ========================= 1 | SettingA | ADefault ------------------------- 2 | SettingB | BDefault ------------------------- </pre> <p>And</p> <p>UserSetting</p> <pre> UserID | SettingID | Value ================================ 1 | 1 | Alice -------------------------------- 1 | 2 | Bob -------------------------------- 2 | 1 | AOverride -------------------------------- </pre> <p>When I create my dbml file, it appropriately links User to <code>UserSetting</code> and <code>UserSetting</code> to <code>Setting</code> based on the foreign keys set up in the database.</p> <p>What I'm wondering is if its possible to coalesce back from <code>UserSetting</code> to the <code>Setting</code> table if the user hasn't specifically overridden the value in a way that makes sense.</p> <p>Specifically, I'm looking for the following pseudo-code:</p> <pre><code>var user = MyDataContext.Users.SingleOrDefault(u => u.ID == 2); foreach(var setting in user.UserSettings) { Console.Writeline(setting.ID + "|" + setting.Value); } </code></pre> <p>To output something like this:</p> <pre> 1 | AOverride 2 | BDefault </pre> <p>Without modification, user.UserSettings will only contain the values that have specifically been overridden, so it will only return:</p> <pre> 1 | AOverride </pre> <p>Any ideas? Or could someone with more rep please help me rephrase this, since it probably isn't exactly clear? :)</p>

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