SQL previous value - sql

Question

I've created a SQL statement:
SELECT
ROW_NUMBER() OVER (ORDER BY Q2.FUNCTIONAL_LOCATION) AS Rowy,
Q1.FACT_MEASUREMENT_KEY,
CONVERT(VARCHAR,Q1.Doc_Time,102) AS TIME
FROM
dbo.DIM_PROJECT_TECH_OBJ Q2
INNER JOIN
dbo.FACT_MEASUREMENT Q1 ON (Q1.PROJECT_TECH_OBJ_KEY = Q2.PROJECT_TECH_OBJ_KEY)
WHERE
Q1.Measurement_Position = 'XXX'
Getting this result:
1 16124 08:00:00
2 53969 12:30:00
3 54282 17:15:00
4 55231 18:00:00
5 56196 15:00:00
6 16123 08:00:00
7 55393 12:30:00
8 55423 09:30:00
9 54283 08:00:00
My goal is to obtain the "Record-1" TIME in each row (expecting an error for the first one), like this:
1 16124 8:00:00
2 53969 12:30:00 8:00:00
3 54282 17:15:00 12:30:00
4 55231 18:00:00 17:15:00
5 56196 15:00:00 18:00:00
6 16123 8:00:00 15:00:00
7 55393 12:30:00 8:00:00
8 55423 9:30:00 12:30:00
9 54283 8:00:00 9:30:00
I've already failed trying to use:
ROW_NUMBER() OVER (PARTITION BY Q1.FACT_MEASUREMENT_KEY ORDER BY Q1.FACT_MEASUREMENT_KEY ) AS RowP
But I got error code 102.
This version of SQL Server does not support LAG statements.
Thanks in advance for any suggestion/help.
Regs

Answer 1

You can do this with a self join on the results of your query:
WITH t as (
SELECT ROW_NUMBER() OVER (ORDER BY Q2.FUNCTIONAL_LOCATION) AS Rowy,
Q1.FACT_MEASUREMENT_KEY,
CONVERT(VARCHAR(255), Q1.Doc_Time, 102) AS TIME
FROM dbo.DIM_PROJECT_TECH_OBJ Q2 INNER JOIN
dbo.FACT_MEASUREMENT Q1
ON Q1.PROJECT_TECH_OBJ_KEY = Q2.PROJECT_TECH_OBJ_KEY
WHERE Q1.Measurement_Position = 'XXX'
)
select t.*, tprev.time
from t left join
t tprev
on tprev.rowy = t.rowy - 1;
When you upgrade to SQL Server 2012+, you can replace this with lag().
Also, when you use varchar() (and related types in SQL Server), always use a length. SQL Server has different default lengths in different contexts -- and the default might not be good enough in some cases.