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POSQL joining three tables to result in two columns, based on a DATE condition
 

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  1. POSQL joining three tables to result in two columns, based on a DATE condition
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    <p>Suppose I have three tables like this:</p> <pre><code>TABLE_X TABLE_Y TABLE_Z --------------------------------------- 2012/1/1 a b 2012/1/2 a b ... a b 2012/3/17 a b 2012/3/18 a b 2012/3/19 a b ... a b 2012/12/22 a b 2012/12/23 a b 2012/12/24 a b ... a b 2013/1/1 a b </code></pre> <p>I need to do a view that uses GETDATE() as a condition. All values on and in the past of GETDATE() will take on <code>TABLE_Y</code> cols. All values in the future of GETDATE() will take on <code>TABLE_Z</code> cols.</p> <pre><code>view_TABLE_X_JOIN_Y_Z --------------------- 2012/1/1 a 2012/1/2 a ... a 2012/3/17 a 2012/3/18 a 2012/3/19 a ... a 2012/12/22 a GETDATE() a 2012/12/24 b ... b 2013/1/1 b 2013/1/2 b </code></pre> <p>What I have tried:</p> <pre><code>SELECT x.Date ,CASE WHEN GETDATE() &gt; x.Date THEN z.Value ELSE y.Value END AS Value FROM TABLE_X x LEFT JOIN TABLE_Y y ON x.Date = y.Date LEFT JOIN TABLE_Z z ON x.Date = z.Date </code></pre> <p>The problem is that dates are not perfect FK references. i.e. Dates in TABLE_X is complete, but they are missing in some places in Y and Z.</p>
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    1. USKyle
    1. USKyle
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    1. COSo what seems to be the problem? Do you have a concrete question regarding something you have tried ?
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      1. USaviad
    2. CO@aviad I have edited the question for further clarifications.
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      1. USKyle
    3. COAnd what do you want to do when a date is missing? Skip that line? Consider it 'long ago'? For what that matters: there are no duplicates?
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      1. USConfusion
 

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