I'll take that as a no :hehe:

Anyway, here's what I'm generally trying to do:

CREATE TABLE testsql (

cid integer,

ctime datetime,

cgm integer);

INSERT INTO testsql VALUES

('1', '2012-01-01 07:00', '1'),

('1', '2012-01-01 07:01', '1'),

('1', '2012-01-01 07:02', '1'),

('1', '2012-01-01 07:03', NULL),

('1', '2012-01-01 07:04', NULL),

('1', '2012-01-01 07:05', '5'),

('1', '2012-01-01 07:06', '5'),

('1', '2012-01-01 07:07', '5'),

('1', '2012-01-01 07:08', NULL),

('1', '2012-01-01 07:09', NULL),

('1', '2012-01-01 07:10', NULL),

('1', '2012-01-01 07:11', NULL),

('2', '2013-05-02 07:12', '24'),

('2', '2013-05-02 07:13', '24'),

('2', '2013-05-02 07:14', '24'),

('2', '2013-05-02 07:15', NULL),

('2', '2013-05-02 07:16', NULL),

('2', '2013-05-02 07:17', '44'),

('2', '2013-05-02 07:18', '44'),

('2', '2013-05-02 07:19', NULL),

('2', '2013-05-02 07:20', '4'),

('2', '2013-05-02 07:21', '4'),

('2', '2013-05-02 07:22', '4');

And here's the query

WITH C (id, pt, gm, dr) as (

SELECT cid, ctime, cgm,

dense_rank() over (partition by cid, cgm order by cid, ctime) as dr

FROM testsql

)

SELECT id, pt, gm,

CASE WHEN gm IS NULL THEN

LAG(gm, cast(c.DR as int)) OVER (PARTITION BY id ORDER BY id, pt)

ELSE gm END as gm2

FROM C

ORDER BY id, pt, gm

There's one result towards the end that is still NULL, rather than being filled in with a LAG value, like the rest in the CASE column are.

Any suggestions?