How often have you needed to start a sequence of numbers at other than 1 or 0?

  • Steve Collins wrote:

    I use 2 monster .sql scripts to answer SSC/SO questions.  One currently has 13,787 lines and contains 32 occurrences of 'fnTally' of which 24 specify the sequence begin with 1.  Two has 6,859 lines and contains 14 occurrences of fnTally of which 9 specify beginning with a 1.  In total 33/46 or about 72%.

    Awesome stats.  Thank you good sir.  And, based on your previous replies, the other 13 or so all start at "0"?

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".
    "Dear Lord... I'm a DBA so please give me patience because, if you give me strength, I'm going to need bail money too!"

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • I dug around in the system I work with daily and I found:

     join numbers n on n.n between p.startYM/100 and p.endYM/100

    The values where would be something like 2019 to 2021. (That is, years.).

    In a unit test I found:

     INSERT OrganizationUnit(ouid)
    SELECT n
    FROM Numbers
    WHERE n BETWEEN 1 AND 1000
    UNION ALL
    SELECT n
    FROM Numbers
    WHERE n BETWEEN 10001 AND 11000

    I don't recall exactly how I use the second set, but presumably I add 10000 to the ouids somewhere.

    In any case, the choice of 1 to 1000 is entirely arbitrary. I could just as well have taken 1211 to 2210.

     

    [font="Times New Roman"]Erland Sommarskog, SQL Server MVP, www.sommarskog.se[/font]

  • Thanks, Erland.  Interesting use case for the year/100 stuff.

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".
    "Dear Lord... I'm a DBA so please give me patience because, if you give me strength, I'm going to need bail money too!"

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • Jeff Moden wrote:

    Awesome stats.  Thank you good sir.  And, based on your previous replies, the other 13 or so all start at "0"?

    Yes, the other 13 start with 0, meaning 'dbo.fnTally(0, ...)'.  That's how the function is being called but many times a constant is added to the sequence either in the SELECT list or as a CROSS JOIN'ed calculated value.

    Aus dem Paradies, das Cantor uns geschaffen, soll uns niemand vertreiben können

  • Here is another example based on what I found to day:

    SELECT char(n) FROM numbers WHERE n BETWEEN acsii('A') AND ascii('Z')

    In the actual example I found when from 0 to 31, because my colleague wanted to deal with control characters, but you get the idea.

     

    [font="Times New Roman"]Erland Sommarskog, SQL Server MVP, www.sommarskog.se[/font]

  • Erland Sommarskog wrote:

    Here is another example based on what I found to day:

    SELECT char(n) FROM numbers WHERE n BETWEEN acsii('A') AND ascii('Z')

    In the actual example I found when from 0 to 31, because my colleague wanted to deal with control characters, but you get the idea.

    That a good "cheater" way to do things if you don't have those key values memorized.  It would also be interesting to see what they were doing in the rest of the query for that particular use of a Numbers table.  It IS one of the very few examples I was thinking of where you might not want to start at "0" or "1" but could easily work around it.

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".
    "Dear Lord... I'm a DBA so please give me patience because, if you give me strength, I'm going to need bail money too!"

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • It would also be interesting to see what they were doing in the rest of the query for that particular use of a Numbers table.

    Actually, I had to rewrite the query, because it relied on undefined behaviour. The purpose was to remove all control characters. It went

    SELECT @xmlstr = replace(@xmlstr, char(n), '') FROM numbers WHERE number n BETWEEN 0 AND 31

    This XML is coming from another system, and apparently the XML is sometimes garbled.

    A second problem is that this will never work for char(0) since that is undefined character unless you cast to a binary collation. A third problem is that the numbers table in questions starts on 1...

    I rewrote the operation using transpose. Still using numbers, but I had to compensate for the missing 0.

     

    [font="Times New Roman"]Erland Sommarskog, SQL Server MVP, www.sommarskog.se[/font]

  • Sounds like a road trip to the data provider with a pork chop cannon may be in order. 😀

    Yeah... I know.  It didn't work for me either. All I got was a "This is the way we've always done it" answer.  No interest in doing it right.

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.
    "Change is inevitable... change for the better is not".
    "Dear Lord... I'm a DBA so please give me patience because, if you give me strength, I'm going to need bail money too!"

    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

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