Re: Compound index and unique

From: Fred Taylor (ftaylor_at_mvps.org!REMOVE)
Date: 02/19/05

  • Next message: shall_at_uaex.edu: "Newbie SQL Left Outer Join"
    Date: Sat, 19 Feb 2005 11:15:33 -0700
    
    

    Yes, that is the purpose of GROUP BY, to create groups of like items. The
    MIN() will return the earliest date within that group.

    -- 
    Fred
    Microsoft Visual FoxPro MVP
    "Charles" <clsuhr@cox.net> wrote in message 
    news:a20f11tqnqmosjdc71afcsrsgtmse0r27g@4ax.com...
    > On Sat, 19 Feb 2005 11:00:31 -0700, "Fred Taylor"
    > <ftaylor@mvps.org!REMOVE> wrote:
    >
    >>Forget about using a UNIQUE index, you're just asking for trouble and/or
    >>corruption.
    >>
    >>If you need a list for display purposes, then do a SQL SELECT using the
    >>MIN() SQL function:
    >>
    >>SELECT item,MIN(yourdate) FROM yourtable GROUP BY item INTO CURSOR
    >>somecursor
    >
    >
    > The list is then link back to an cursor to replace the earliest date
    > all items with the earliest I get from the filtered or subset I have.
    > Then use the earliest date to determine a offset to the start of the
    > other activity.
    >
    > So the grouping by will return me my uniqueness of the item?
    >
    > Thanks for the quick response. 
    

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