Compare dates

• -Syd-

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  August 2, 2011 at 9:44 am

  #254797

  I have some data, with differents date.

  Without making a subquery, is there a function on 2008r2 to compare which is the nearest date on the table to today?

  Thank you very much.

• PaulB-TheOneAndOnly

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  August 2, 2011 at 9:58 am

  #1362294

  -Syd- (8/2/2011)

  ---

  I have some data, with differents date.

  Without making a subquery, is there a function on 2008r2 to compare which is the nearest date on the table to today?

  No silver bullet as far as I know.

  _____________________________________
  Pablo (Paul) Berzukov

  Author of Understanding Database Administration available at Amazon and other bookstores.

  Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.

• -Syd-

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  August 2, 2011 at 10:02 am

  #1362300

  Thank you. So if there any way to compare which the nearest date on a table?

  But it cant be order DESC by date place a TOP 1 on the select clause.

• PaulB-TheOneAndOnly

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  August 2, 2011 at 10:10 am

  #1362310

  -Syd- (8/2/2011)

  ---

  Thank you. So if there any way to compare which the nearest date on a table?

  But it cant be order DESC by date place a TOP 1 on the select clause.

  That would certainly work.

  Let's say you are looking for the previous "order" of a particular "customer" then subquery should select top 1 order_date from order_table where customer = "customer you are looking for" order by order_date desc. an Index on (customer,order_date) would provide the best performance for this particular solution.

  _____________________________________
  Pablo (Paul) Berzukov

  Author of Understanding Database Administration available at Amazon and other bookstores.

  Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.

• ChrisM@Work

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  August 2, 2011 at 10:22 am

  #1362321

  -- make a sample table with some dates in it

  DROP TABLE #Dates

  CREATE TABLE #Dates (RandomDate DATETIME)

  INSERT INTO #Dates (RandomDate)

  SELECT Dateval = GETDATE() + n.RN

  FROM (SELECT TOP 100 RN = ROW_NUMBER() OVER(ORDER BY NAME) - 50 FROM sys.COLUMNS) n

  -- eyeball it

  --SELECT * FROM #Dates

  -- get nearest date before and after GETDATE()

  SELECT *

  FROM (

  SELECT RowID = 1, ACloseDate = MAX(RandomDate) FROM #Dates WHERE RandomDate < GETDATE()

  UNION

  SELECT 2, MIN(RandomDate) FROM #Dates WHERE RandomDate > GETDATE()

  ) d

  ^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

  For fast, accurate and documented assistance in answering your questions, please read this article.
  Understanding and using APPLY, (I) and (II) Paul White
  Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden

• -Syd-

  Mr or Mrs. 500

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  August 2, 2011 at 10:51 am

  #1362348

  Thank you all very much.

  Regards.