It seems that you have a poor design and that's making everyone confused. You should review what's going on here.

That said, this might help you:

CREATE TABLE SampleData(

idint,

val1varchar(50),

val2 varchar(50));

INSERT INTO SampleData

VALUES

(1,'red', NULL),

(1,'blue',NULL),

(1,'green','round'),

(1,NULL,'square');

WITH val1s AS(

SELECT id,

val1,

ROW_NUMBER() OVER(PARTITION BY id ORDER BY val1 DESC) rn

FROM SampleData

WHERE val1 IS NOT NULL

),

val2s AS(

SELECT id,

val2,

ROW_NUMBER() OVER(PARTITION BY id ORDER BY val2 DESC) rn

FROM SampleData

WHERE val2 IS NOT NULL

)

SELECT ISNULL( v1.id, v2.id) id,

v1.val1,

v2.val2

FROM val1s v1

FULL

JOIN val2s v2 ON v1.id = v2.id AND v1.rn = v2.rn

GO

DROP TABLE SampleData

Next time, please post sample data and expected results the same way I did here to prevent us from having to do additional work (we're not paid for helping).