Here is another solution to the problem:

CREATE TABLE dbo.UpdateGaps(

MachineID int NOT NULL,

RecordedDate datetime NOT NULL,

Pressure float NULL,

CONSTRAINT PK_UpdateGaps PRIMARY KEY CLUSTERED (MachineID,RecordedDate)

)

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-02', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-03', 300);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-04', 300);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-05', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-06', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-07', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-08', 330);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-09', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (60, '2012-10-10', 300);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-02', 380);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-03', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-04', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-05', 350);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-06', 350);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-07', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-08', 0);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-09', 400);

INSERT dbo.UpdateGaps (MachineID, RecordedDate, Pressure) VALUES (97, '2012-10-10', 0);

GO

with Base0Data as (

select

MachineID,

RecordedDate,

Pressure,

rn = row_number() over (partition by MachineID, case when Pressure = 0 then 0 else 1 end order by RecordedDate)

from

dbo.UpdateGaps

)

,BaseData as (

select

MachineID,

RecordedDate,

Pressure,

GrpDate = dateadd(dd,-rn,RecordedDate),

rn,

rn1 = row_number() over (partition by MachineID, dateadd(dd,-rn,RecordedDate) order by dateadd(dd,-rn,RecordedDate))

from

Base0Data

)

--select * from BaseData where Pressure = 0

select

bd1.MachineID,

bd1.RecordedDate,

Pressure = case when bd1.Pressure = 0 then coalesce(bd2.Pressure, bd1.Pressure) else bd1.Pressure end

from

BaseData bd1

left outer join BaseData bd2

on (bd1.MachineID = bd2.MachineID

and dateadd(dd, -bd1.rn1, bd1.RecordedDate) = bd2.RecordedDate)

order by

bd1.MachineID,

bd1.RecordedDate;

go

drop table dbo.UpdateGaps;

go