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POSQL to get list of dates as well as days before and after without duplicates
 

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    <p>I need to display a list of dates, which I have in a table</p> <pre><code>SELECT mydate AS MyDate, 1 AS DateType FROM myTable WHERE myTable.fkId = @MyFkId; </code></pre> <blockquote> <p>Jan 1, 2010 - 1<br> Jan 2, 2010 - 1<br> Jan 10, 2010 - 1</p> </blockquote> <p>No problem. However, I now need to display the date before and the date after as well with a different DateType.</p> <blockquote> <p>Dec 31, 2009 - 2<br> Jan 1, 2010 - 1<br> Jan 2, 2010 - 1<br> Jan 3, 2010 - 2<br> Jan 9, 2010 - 2<br> Jan 10, 2010 - 1<br> Jan 11, 2010 - 2 </p> </blockquote> <p>I thought I could use a union</p> <pre><code>SELECT MyDate, DateType FROM ( SELECT mydate - 1 AS MyDate, 2 AS DateType FROM myTable WHERE myTable.fkId = @MyFkId; UNION SELECT mydate + 1 AS MyDate, 2 AS DateType FROM myTable WHERE myTable.fkId = @MyFkId; UNION SELECT mydate AS MyDate, 1 AS DateType FROM myTable WHERE myTable.fkId = @MyFkId; ) AS myCombinedDateTable </code></pre> <p>This however includes duplicates of the original dates.</p> <blockquote> <p>Dec 31, 2009 - 2<br> Jan 1, 2010 - 2<br> Jan 1, 2010 - 1<br> Jan 2, 2010 - 2<br> Jan 2, 2010 - 1<br> Jan 3, 2010 - 2<br> Jan 9, 2010 - 2<br> Jan 10, 2010 - 1<br> Jan 11, 2010 - 2 </p> </blockquote> <p>How can I best remove these duplicates? I am considering a temporary table, but am unsure if that is the best way to do it.</p> <p>This also appears to me that it may provide performance issues as I am running the same query three separate times.</p> <p>What would be the best way to handle this request?</p>
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    1. USNathan Koop
    1. USNathan Koop
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      1. POSQL to get list of dates as well as days before and after without duplicates
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    1. COThey are not technically duplicates, as the date types are different. Which date type do you want to show when there are duplicates?
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      1. USRedFilter
    2. CO@OrbMan, you are correct, I would like to display Type 1 if the date is repeated and ignore Type 2.
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      1. POSQL to get list of dates as well as days before and after without duplicates
      1. USNathan Koop
    3. COwhere does `Jan 1, 2009 - 2` come from ... (notice the jan and 2009).
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      1. POSQL to get list of dates as well as days before and after without duplicates
      1. USGabriele Petrioli
 

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