|
|
Posted by Dan Guzman on 06/26/07 12:42
> >When using the 'Last' function, do you have to have the columns sorted
>>by when they were entered?
>
> What 'Last' function? I did not use any such function, and have not
> heard of any such function.
FIRST and LAST are non-relational aggregate functions in Access. In the
latest version of Access, these return the first and last values of an
ordered set. However, the returned values are arbitrary when the result is
unordered and I don't think the result is well-defined in many cases.
--
Hope this helps.
Dan Guzman
SQL Server MVP
"Roy Harvey" <roy_harvey@snet.net> wrote in message
news:hh008312fs128vcm5aqt5h5ichnpsb5g3c@4ax.com...
> >When using the 'Last' function, do you have to have the columns sorted
>>by when they were entered?
>
> What 'Last' function? I did not use any such function, and have not
> heard of any such function.
>
> MAX() is unrelated to order. SQL tables are not ordered anyway, any
> order you need must be built into the data so that you can use ORDER
> BY to control the order of the results when querying.
>
> TOP is dependent on order (contolled using ORDER BY), but I did not
> use TOP.
>
> Roy Harvey
> Beacon Falls, CT
>
> On Mon, 25 Jun 2007 17:29:08 -0000, mcolson <mcolson1590@gmail.com>
> wrote:
>
>>On Jun 25, 11:01 am, Roy Harvey <roy_har...@snet.net> wrote:
>>> What exactly is the datatype of Shift_Date? What action are you
>>> trying to take based on the comparison?
>>>
>>> If you want to compare them inside a SELECT this might get you
>>> started.
>>>
>>> SELECT A.ShiftDate as LastShiftDate,
>>> B.ShiftDate as NextToLastShiftDate
>>> FROM (SELECT * FROM TheTable
>>> WHERE Row_Index =
>>> (SELECT MAX(Row_Index) FROM TheTable) as A
>>> CROSS JOIN
>>> (SELECT * FROM TheTable
>>> WHERE Row_Index =
>>> (SELECT MAX(Row_Index)-1 FROM TheTable) as B
>>>
>>> Roy Harvey
>>> Beacon Falls, CT
>>>
>>> On Mon, 25 Jun 2007 15:44:07 -0000, mcolson <mcolson1...@gmail.com>
>>> wrote:
>>>
>>> >I am trying to compare the last two values in the same column of a
>>> >table. First of all, I have a column titled Row_Index that uses an
>>> >index which starts at 1 and increments by 1. What I am trying to do
>>> >is compare the values in the column 'Shift_Date' for the maximum value
>>> >of Row_Index and the (maximum value - 1) of Row_Index. I've been
>>> >trying to declare two strings, setting each string equal to one of my
>>> >values, and then comparing the strings. But this doesn't seam to be
>>> >working right. I'm not sure I am even declaring the strings
>>> >correctly. Does anyone know how I can do this. A sample of what one
>>> >of my values looks like in Shift_Date is ' 6/25/2007'.
>>
>>When using the 'Last' function, do you have to have the columns sorted
>>by when they were entered?
Navigation:
[Reply to this message]
|