How to check the previous row value - sql-server

Question

Following is the model data in my table.
Data:
Date Worked Hours IsLate
8/1/2013 8:03:00 No
8/2/2013 10:52:00 No
8/3/2013 8:43:00 Yes
8/4/2013 9:26:00 No
IsLate column to be updated as 'Yes' if previous day worked hours is equal to 10 hours. How can I calculate the previous row value is equal to 10 hours or not.
Please help me out.

Answer 1

Query:
SQLFIDDLEExample
with table5
as (
SELECT Date,
[Worked Hours],
IsLate,
ROW_NUMBER() OVER (ORDER BY Date ASC, [Worked Hours] ASC) AS RowNumber1
FROM Table1
)
SELECT t1.Date,
t1.[Worked Hours],
t1.IsLate,
CASE WHEN LEFT(t2.[Worked Hours],2) = '10'
THEN 'Equal'
ELSE 'Not Equal' END AS isequal
FROM table5 t1
LEFT JOIN table5 t2
ON t1.RowNumber1 - 1 = t2.RowNumber1
Result:
| DATE | WORKED HOURS | ISLATE | ISEQUAL |
|-------------------------------|--------------|--------|-----------|
| August, 01 2013 00:00:00+0000 | 8:03:00 | No | Not Equal |
| August, 02 2013 00:00:00+0000 | 10:52:00 | No | Not Equal |
| August, 03 2013 00:00:00+0000 | 8:43:00 | Yes | Equal |
| August, 04 2013 00:00:00+0000 | 9:26:00 | No | Not Equal |
If you want just update table use this:
SQLFIDDLEExample
UPDATE Table1
SET [IsLate] = ISNULL((SELECT TOP 1 CASE WHEN LEFT(t1.[Worked Hours],2) = '10'
THEN 'Equal'
ELSE 'Not' END
FROM Table1 t1
WHERE t1.Date < Table1.Date
ORDER BY t1.Date DESC), 'Not')
Result:
| DATE | WORKED HOURS | ISLATE |
|-------------------------------|--------------|--------|
| August, 01 2013 00:00:00+0000 | 8:03:00 | Not |
| August, 02 2013 00:00:00+0000 | 10:52:00 | Not |
| August, 03 2013 00:00:00+0000 | 8:43:00 | Equal |
| August, 04 2013 00:00:00+0000 | 9:26:00 | Not |

Answer 2

IF 10 <= (SELECT DATEPART(hh, Worked_Hours) from Data)
Begin
Update Data set isLate = 'No'
where ..
End

Answer 3

update yourtable
set late='yes'
from yourtable
where
(select top 1 datepart(hh,worked)
from yourtable t2
where t2.workdate<yourtable.workdate order by workdate desc)=10

Answer 4

How about this?
declare #d table (WorkedDate date,WorkedHours time,IsLate varchar(10));
insert #d select '8/1/2013','8:03',null;
insert #d select '8/2/2013','10:52',null;
insert #d select '8/3/2013','8:43',null;
insert #d select '8/4/2013','9:26',null;
update #d set IsLate=case when exists (select WorkedHours from #d p where p.WorkedDate=dateadd(day,-1,d.WorkedDate) and WorkedHours>'10:00') then 'Yes' else 'No' end
from #d d;
select * from #d;