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[Ian]

posted to SQL Queries English with no reponse -- sorry for the repeat

I have a single table with 5 fields:

READID (key, INT), ID (user identifier, INT), READDATE, TOD (time of day -
as INT 1, 2, 3, ...24), CONSUMPTION (measurement).

I'm looking to return the maximum measurement (CONSUMPTION) from each day
for each user with it's corresponding TOD but having problem when I include
the TOD in the query (it tries to show the max(consumption) for each TOD but
there's only one measurement for each TOD). Is there a way to show the max
consumption each day for each user but also show the corresponding TOD?

SQL statment and result below that
SELECT DISTINCT A.ID, A.DATEREAD, A.TOD, MAX(CONSUMPTION)
FROM DATANORM AS A
WHERE A.DATEREAD > '2008/11/30'
GROUP BY A.ID, A.TOD, A.DATEREAD
--HAVING CONSUMPTION = MAX(CONSUMPTION)
ORDER BY ID,DATEREAD

Here is a sample of the current query returning every TOD
USER DATE TOD CONSUMPTION
1 2008-12-01 3 4.740000
1 2008-12-01 10 4.400000
1 2008-12-01 17 4.680000
1 2008-12-01 5 3.990000
1 2008-12-01 24 6.560000
1 2008-12-01 12 3.570000
1 2008-12-01 7 4.320000
1 2008-12-01 14 3.530000
1 2008-12-01 19 4.880000
1 2008-12-01 21 5.210000
1 2008-12-01 2 4.060000
1 2008-12-01 9 6.370000
1 2008-12-01 4 4.010000
1 2008-12-01 16 3.960000
1 2008-12-01 23 4.670000
1 2008-12-01 18 5.590000
1 2008-12-01 11 3.770000
1 2008-12-01 6 4.410000
1 2008-12-01 1 5.950000
1 2008-12-01 13 4.450000
1 2008-12-01 20 4.840000
1 2008-12-01 8 4.640000
1 2008-12-01 22 5.040000
1 2008-12-01 15 3.940000
1 2008-12-02 5 5.460000
1 2008-12-02 12 4.390000
1 2008-12-02 10 4.810000
1 2008-12-02 17 5.020000
1 2008-12-02 19 5.730000
1 2008-12-02 3 5.590000
1 2008-12-02 15 4.710000
1 2008-12-02 13 5.510000

 

[John Spencer]

Use a sub-query in the FROM clause. The following may return more than one
record for any date if there is a tie for the max of Consumption on that date.

SELECT DataNorm.*
FROM DataNorm INNER JOIN
(SELECT DateRead, Max(Consumption) as TheMax
FROM DataNorm
GROUP BY DateRead)
ON DataNorm.DateRead = Temp.DateRead
AND DataNorm.Consumption = Temp.TheMax
WHERE DataNorm.DATEREAD > '2008/11/30'
ORDER BY ID,DATEREAD

John Spencer
Access MVP 2002-2005, 2007-2009
The Hilltop Institute
University of Maryland Baltimore County

 

[Anne]

You could combine the two fields for calculation. Format the fields to show
even lengths to make separation easier.
FormatCon: Format([consumption],"###0.000000")
FormatTod: Format([Tod],"00")
ConTod: [FormatCon] & "-" & [FormatTod]
new query max those three fields.
next query: Consumption: Left([maxofcontod],8), TOD: Right([maxofcontod],2)
You can then reformat the numbers back tohow you want them.


Actually for those

 

[Ian]

I'm getting a sytax error with the ON clause (line 7). Is it in the correct
place?

 

[Ian]

Think I figured it out -- did not specify the nested query as being called
Temp but it's not working quite right John -- it's showing the maxconsump per
day (e.g. 1 reading per day). I'd like it to show the max reading for each
user each day.

 

[Ian]

SUCCESS!!!! THANK YOU SO MUCH JOHN.

SELECT DataNorm.*
FROM DataNorm INNER JOIN
(SELECT DateRead, ID, Max(Consumption) as TheMax
FROM DataNorm
GROUP BY DateRead, ID) Temp
ON DataNorm.DateRead = Temp.DateRead
AND DataNorm.Consumption = Temp.TheMax
AND DATANORM.ID = Temp.ID
WHERE DataNorm.DATEREAD > '2008/11/30'
ORDER BY ID, DATEREAD