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Asked: 2026-06-04T00:48:23+00:00

I have two tables as follows: TableOne – RawDataId int (pk) – TimeStamp DateTime

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I have two tables as follows:

TableOne
– RawDataId int (pk)
– TimeStamp DateTime
– BuildingID int

TableTwo
– RawDataId int (pk/fk)
– MeterId int (pk)
– Value real

The MeterId is not unique and repeats multiple times (but always in equal number). The two tables join together no problem. I am able to select the top 15 rows and order the by time stamp, giving me the latest value for each meter (15 in total, each with a time stamp). However, I also need to get the Value of each meter from a previous time (exactly 1440 and 1439 minutes earlier) – if that makes any sense.

So after the query is run, I need a table with the columns from TableOne and TableTwo, but with two additional columns for ValueB and ValueC (B been the value 1440 minutes earlier, and C 1439 earlier). Ive been playing around with his all day and most of last night, and I’m slowly losing the plot.

Any help would be appreciated.
Thanks peeps.

— Update

I’ve included the actual table schema below, together with some sample data.

CREATE TABLE [dbo].[TableOne](
[RawDataId] [bigint] IDENTITY(1,1) NOT NULL,
[TimeStamp] [datetime] NOT NULL,
[BuildingId] [int] NULL,
CONSTRAINT [TableOne_PK] PRIMARY KEY CLUSTERED 

CREATE TABLE [dbo].[TableTwo](
[MeterId] [bigint] NOT NULL,
[RawDataId] [bigint] NOT NULL,
[Value] [real] NULL,
 CONSTRAINT [TableTwo_PK] PRIMARY KEY CLUSTERED

The sample data for the last 30 records from TableOne:

RawDataId, TimeStamp, BuildingId
21677   2012-05-16 00:03:00.000 1
21678   2012-05-16 00:03:00.000 1
21679   2012-05-16 00:03:00.000 1
21680   2012-05-16 00:03:00.000 1
21681   2012-05-16 00:03:00.000 1
21682   2012-05-16 00:03:00.000 1
21683   2012-05-16 00:03:00.000 1
21684   2012-05-16 00:03:00.000 1
21685   2012-05-16 00:03:00.000 1
21686   2012-05-16 00:03:00.000 1
21687   2012-05-16 00:03:00.000 1
21688   2012-05-16 00:03:00.000 1
21689   2012-05-16 00:03:00.000 1
21690   2012-05-16 00:03:00.000 1
21691   2012-05-16 00:03:00.000 1
21662   2012-05-16 00:02:00.000 1
21663   2012-05-16 00:02:00.000 1
21664   2012-05-16 00:02:00.000 1
21665   2012-05-16 00:02:00.000 1
21666   2012-05-16 00:02:00.000 1
21667   2012-05-16 00:02:00.000 1
21668   2012-05-16 00:02:00.000 1
21669   2012-05-16 00:02:00.000 1
21670   2012-05-16 00:02:00.000 1
21671   2012-05-16 00:02:00.000 1
21672   2012-05-16 00:02:00.000 1
21673   2012-05-16 00:02:00.000 1
21674   2012-05-16 00:02:00.000 1
21675   2012-05-16 00:02:00.000 1
21676   2012-05-16 00:02:00.000 1

Sample for TableTwo:

MeterId, RawDataId, Value
15  21691   7722613
14  21690   908944
13  21689   4982947
12  21688   3821899
11  21687   6
10  21686   0
9   21685   0
8   21684   5761656
7   21683   4240048
6   21682   1541372
5   21681   283223
4   21680   1.298603E+07
3   21679   388137
2   21678   876121
1   21677   0
15  21676   7722615
14  21675   908944
13  21674   4982947
12  21673   3821899
11  21672   5
10  21671   0
9   21670   0
8   21669   5761656
7   21668   4240052
6   21667   1541372
5   21666   283223
4   21665   1.298604E+07
3   21664   388137
2   21663   876122
1   21662   0

A meter reading is written to the tables every 1 (hence the time stamp). When select the top 15 records (sorted by TimeStamp, to give me the latest values), I also need to get the values of that meter 1440 and 1439 minutes ago (relative to the latest TimeStamp). I hope this makes it clearer.

So far, my SQL query looks like this:

SELECT TOP 15 * FROM (Select TableOne.[RawDataId], 
[TimeStamp], BuildingId, MeterId, `enter code here`Value 
FROM [TableOne]
INNER JOIN TableTwo ON
TableOne = TableTwo) as PS
ORDER BY [TimeStamp];

The query gives me the follow, but I need the additional two columns with the value of the meter 1440 and 1439 minutes ago, relative to the TimeStamp:

RawDataId, TimeStamp, BuildingId, MeterId, Value
21677   2012-05-16 00:03:00.000 1   1   0
21678   2012-05-16 00:03:00.000 1   2   876121
21679   2012-05-16 00:03:00.000 1   3   388137
21680   2012-05-16 00:03:00.000 1   4   1.298603E+07
21681   2012-05-16 00:03:00.000 1   5   283223
21682   2012-05-16 00:03:00.000 1   6   1541372
21683   2012-05-16 00:03:00.000 1   7   4240048
21684   2012-05-16 00:03:00.000 1   8   5761656
21685   2012-05-16 00:03:00.000 1   9   0
21686   2012-05-16 00:03:00.000 1   10  0
21687   2012-05-16 00:03:00.000 1   11  6
21688   2012-05-16 00:03:00.000 1   12  3821899
21689   2012-05-16 00:03:00.000 1   13  4982947
21690   2012-05-16 00:03:00.000 1   14  908944
21691   2012-05-16 00:03:00.000 1   15  7722613
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1 Answer

  1. Editorial Team

    Without seeing a data (and maybe query) sample, it’s really hard to understand the problem. If I’m understanding correctly, this should work:

    SELECT
(
SELECT TOP 1 Value
FROM TableOne t1 join TableTwo t2 ON t1.RawDataId = t2.RawDataId
WHERE t1.RawDataId IN (
SELECT RawDataId FROM TableTwo WHERE MeterId = tbl.MeterId
) and TimeStamp = DATEADD(mi, -1440, tbl.TimeStamp)
) as ValueB,
(
SELECT TOP 1 Value
FROM TableOne t1 join TableTwo t2 ON t1.RawDataId = t2.RawDataId
WHERE t1.RawDataId IN (
SELECT RawDataId FROM TableTwo WHERE MeterId = tbl.MeterId
) and TimeStamp = DATEADD(mi, -1439, tbl.TimeStamp)
) as ValueC
FROM TableTwo tbl
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