Question

I have table in Ms SQL Server 2005 (2008) in following structure

ID Name     AddDate                   AmendDate                 Status
-----------------------------------------------------------------------
1  Jason    2012-09-03 08:01:00.000   2012-09-03 14:02:00.000   Amended
2  Robert   2012-09-03 08:05:00.000   NULL                      New
3  Celia    2012-09-03 08:10:00.000   2012-09-03 14:02:00.000   Amended
4  Jason    2012-09-03 14:02:00.000   NULL                      New
5  Robert   2012-09-03 14:03:00.000   2012-09-03 20:02:00.000   Amended
6  Celia    2012-09-03 14:07:00.000   2012-09-03 20:02:00.000   Amended
7  Jason    2012-09-03 20:00:00.000   NULL                      New
8  Robert   2012-09-03 20:02:00.000   NULL                      New
9  Celia    2012-09-03 20:04:00.000   NULL                      New

routine runs three times per day as snapshot,

please how can I by using SQL Query

1. select all record from morning (or evening) for any of days

2. how can I replace (ISNULL(AmendDate, '2012.09.04')) for column AmendDate where is Null value, in the case when I walking in history, for example returns all row that AddDate <= '2012-09-01' and AmendDate >= '2012-09-02'

3. question is about SELECT - FROM - WHERE - only

Answer 1

To select all records from morning/evening for any of days

select *
from Table t
where t.AddDate > '2012-09-03' 
      and t.AddDate < '2012-09-04'
      and DatePart(HOUR, t.AddDate) < 12 -- Morning
      -- and DatePart(HOUR, t.AddDate) > 18 -- Evening

For the second part (given that the requirement is not very clear) I think you can use Coalesce function with a CTE

;WITH FullData(Id, Name, AddDate, AmendDate, Status)
     AS (SELECT t.Id,
                t.Name,
                t.AddDate,
                COALESCE(t.AmendDate, '2012-09-04'),
                Status
         FROM   Table t)
SELECT *
FROM   FullData d
WHERE  d.AddDate <= '2012-09-01'
       AND t.AmendDate >= '2012-09-02'