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POSelecting unique rows in a set of two possibilities
 

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    <p>The problem itself is simple, but I can't figure out a solution that does it in one query, and here's my "abstraction" of the problem to allow for a simpler explanation:</p> <p><strong>I will let my original explenation stand, but here's a set of sample data and the result i expect:</strong></p> <p>Ok, so here's some sample data, i separated pairs by a blank line</p> <pre><code>------------- | Key | Col | (Together they from a Unique Pair) -------------- | 1 Foo | | 1 Bar | | | | 2 Foo | | | | 3 Bar | | | | 4 Foo | | 4 Bar | -------------- </code></pre> <p>And the result I would expect, <strong>after running the query once</strong>, it need to be able to select this result set in one query:</p> <pre><code>1 - Foo 2 - Foo 3 - Bar 4 - Foo </code></pre> <p><em>Original explenation:</em></p> <p>I have a table, call it <code>TABLE</code> where I have a two columns say <code>ID</code> and <code>NAME</code> which together form the primary key of the table. Now I want to select something where <code>ID=1</code> and then first checks if it can find a row where <code>NAME</code> has the value "John", if "John" does not exist it should look for a row where <code>NAME</code> is "Bruce" - but only return "John" if both "Bruce" and "John" exists or only "John" exists of course.</p> <p>Also note that it should be able to return several rows per query that match the above criteria but with different ID/Name-combinations of course, and that the above explanation is just a simplification of the real problem.</p> <p>I could be completely blinded by my own code and line of thought but I just can't figure this out. </p>
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    1. USConcernedOfTunbridgeWells
    1. USthr
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    1. COCould you please clarify this question by giving an example? i.e. giving minimal data sets and the solutions you want to achieve from them?
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    2. COHow cross platform do you require the answer to be? I could come up with something that would work in SQL Server, but wouldn't in MySQL...
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    3. COGeorgi: I clarified the example with some example data and the result i would expect after one query AviewAnew: Anything is helpful
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