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Sum fields and place into a view if ID's are the same

开发者 https://www.devze.com 2023-03-20 06:24 出处:网络
I have a table of electricity usage over monthly periods in MS Access.I want to create a table or a query that will only display the total sum of electricity usage.Here\'s a sample of my starting tabl

I have a table of electricity usage over monthly periods in MS Access. I want to create a table or a query that will only display the total sum of electricity usage. Here's a sample of my starting table:

ID, Mete开发者_如何学运维rID, DateRead, kWh
--------------------------
1, 15256, 10/9/2010, 1710
2, 15256, 11/1/2010, 4790
3, 15256, 12/1/2010, 5390
4, 15256, 1/1/2011, 7590
5, 12557, 10/1/2010, 681
6, 12257, 11/1/2010, 710
7, 12257, 11/1/2010, 710

And so on. I want to sum the kWh column where the Meter ID's are the same. So it would look like this

MeterID, kWh
------------
15256, Some sum
12257,Some sum

If I were writing this in C I could do this in 2 seconds. Unfortunately, this is my first real journey into SQL/Databases so I'm not very familiar with them. Any help would be appreciated. Sorry if it's trivial.


SELECT MeterID, SUM(kWh) FROM usage GROUP BY MeterID

SUM() is a aggregate function that goes through every row of your query and sums the argument (here kWh). You need the GROUP BY to tell SUM() to add kWh for the corresponding MeterID.

GROUP BY

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