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.
  • Next message: shall_at_uaex.edu: "Newbie SQL Left Outer Join"

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