SQL Server 2008 - Retrieve the nearest non null data - sql

Question

I have two tables: table 1 a package_id and a timestamp column for which I have no weight information available, table 2 a package_id, a timestamp and a weight column where I do have the information.
What I'm trying to do is fill in the table 1 weight information based on table 2 using the following restrictions:
use the closest package_id available ie. for package_id 1 use 2 if available, if not 3 etc
if there is only one weight available use it for all the missing package_id's
if two weights are available, use the higher one ie. for package_id 5, if 4 and 6 are available use 6
The code:
IF OBJECT_ID('tempdb..#TIMEGAPS') IS NOT NULL DROP TABLE #TIMEGAPS
CREATE TABLE #TIMEGAPS (PACK_ID INT, Local_Time DATETIME)
IF OBJECT_ID('tempdb..#REALVALUES') IS NOT NULL DROP TABLE #REALVALUES
CREATE TABLE #REALVALUES (PACK_ID INT, Local_Time DATETIME, WEIGHT INT)
INSERT INTO #TIMEGAPS VALUES
(1,'2018-01-20 18:40:00.000'),
(1,'2018-01-20 18:50:00.000'),
(1,'2018-01-20 19:00:00.000'),
-----------------------------
(7,'2018-01-20 18:40:00.000'),
(7,'2018-01-20 18:50:00.000'),
(7,'2018-01-20 19:00:00.000'),
------------------------------
(12,'2018-01-20 18:40:00.000'),
(12,'2018-01-20 18:50:00.000'),
(12,'2018-01-20 19:00:00.000'),
(12,'2018-01-20 20:00:00.000')
INSERT INTO #REALVALUES VALUES
(2,'2018-01-20 18:40:00.000',50),
(3,'2018-01-20 18:40:00.000',70),
(4,'2018-01-20 18:40:00.000',150),
(5,'2018-01-20 18:40:00.000',60),
(6,'2018-01-20 18:40:00.000',45),
(8,'2018-01-20 18:40:00.000',55),
(9,'2018-01-20 18:40:00.000',25),
---------------------------------
(2,'2018-01-20 18:50:00.000',75),
(3,'2018-01-20 18:50:00.000',80),
(4,'2018-01-20 18:50:00.000',120),
(5,'2018-01-20 18:50:00.000',110),
(11,'2018-01-20 18:50:00.000',30),
---------------------------------
(8,'2018-01-20 19:00:00.000',70)
EDIT:
I've adapted the solution from here which I believe is what I need.
SELECT tg.PACK_ID, tg.Local_Time, p.WEIGHT
FROM #TIMEGAPS tg
OUTER APPLY
(
SELECT TOP 1 *, ABS(tg.PACK_ID - rv.PACK_ID) AS diff
FROM #REALVALUES rv
WHERE (tg.Local_Time = rv.Local_time OR rv.Local_time is null)
ORDER BY CASE WHEN rv.Local_time IS NULL THEN 2 ELSE 1 END,
ABS(rv.PACK_ID- tg.PACK_ID) ASC
) p
EDIT 2:
3. if two weights are available, use the highest PACK_ID ie. for package_id 5, if PACK_ID 4 and PACK_ID 6 are available use 6

Answer 1

Something like this?
It uses a row_number by distance.
SELECT
PACK_ID, Local_Time, WEIGHT
FROM (
SELECT g.PACK_ID, g.Local_Time, v.WEIGHT,
ROW_NUMBER() OVER (PARTITION BY g.PACK_ID, g.Local_Time
ORDER BY ABS(v.PACK_ID - g.PACK_ID), v.PACK_ID DESC) AS RN
FROM #TIMEGAPS AS g
JOIN #REALVALUES AS v ON v.Local_Time = g.Local_Time
) AS q
WHERE RN = 1
ORDER BY PACK_ID, Local_Time

Answer 2

I suppose we can start here. Make sure to initialize your tables before you run this. I assumed that #TIMEGAPS has a weight column based on your output.
DECLARE
#Pack_id INT
, #Weight_id INT
, #mloop INT = 0
DECLARE #possible TABLE (
id INT IDENTITY (1,1)
, pack_id INT
, weight )
BEGIN_LABEL:
SELECT TOP 1 #pack_id = PACK_ID
FROM #TIMEGAPS AS g
WHERE g.WEIGHT IS NULL
ORDER BY PACK_ID ASC
IF #pack_id IS NULL
BEGIN
PRINT 'Done'
EXIT
END
INSERT INTO #possible (pack_id , weight )
SELECT PACK_ID , WEIGHT
FROM #REALVALUES as r
LEFT JOIN #TIMEGAPS as g
ON g.WEIGHT = r.PACK_ID
WHERE g.WEIGHT IS NULL
ORDER BY ABS(#pack_id - PACK_ID) ASC , WEIGHT DESC
SELECT TOP 1 #Weight_id = weight
FROM #possible
ORDER BY id ASC
IF (#Weight_id IS NULL)
BEGIN
RAISERROR('No Weights available' , 18 , 1)
EXIT
END
UPDATE #TIMEGAPS
SET WEIGHT = #Weight_id
WHERE PACK_ID = #Pack_id
SET #mloop = #mloop + 1
IF #mloop > 99
BEGIN
PRINT 'Hit Safety'
EXIT
END
SELECT #Pack_id = NULL , #Weight_id = NULL;
DELETE #possible;
GOTO BEGIN_LABEL
SELECT g.PACK_ID , g.Local_Time , r.WEIGHT
FROM #TIMEGAPS AS g
INNER JOIN #REALVALUES AS r
r.PACK_ID = g.WEIGHT;
Im pretty sure RAISERROR() works in SQL 2008, but you can just replace them with print statements if they don't