SQL Server 2017

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SELECT 9007853627  ORIGINAL_ORDER_NO ,
1        original_order_line_no           , 9008142190   ORDER_NO ,  1      ORDER_LINE_NO 
INTO tab
UNION ALL SELECT 9007853627     ,        2     ,               9008142190 ,  2  
UNION ALL SELECT NULL           ,       NULL  ,                9008142190  , 4   
UNION ALL SELECT NULL            ,      NULL ,                 9008142190   ,5  
4 rows affected

SELECT * FROM tab


ORIGINAL_ORDER_NO
original_order_line_no
ORDER_NO
ORDER_LINE_NO


9007853627
1
9008142190
1

9007853627
2
9008142190
2

null
null
9008142190
4

null
null
9008142190
5


WITH cte AS (
SELECT *, MIN(ORIGINAL_ORDER_NO) OVER(PARTITION BY ORDER_NO) as s
FROM tab
)
UPDATE cte
SET ORIGINAL_ORDER_NO = s
   ,original_order_line_no = ORDER_LINE_NO  
WHERE ORIGINAL_ORDER_NO IS NULL;
Warning: Null value is eliminated by an aggregate or other SET operation.
2 rows affected

SELECT * FROM tab


ORIGINAL_ORDER_NO
original_order_line_no
ORDER_NO
ORDER_LINE_NO


9007853627
1
9008142190
1

9007853627
2
9008142190
2

9007853627
4
9008142190
4

9007853627
5
9008142190
5

ORIGINAL_ORDER_NO	original_order_line_no	ORDER_NO	ORDER_LINE_NO
9007853627	1	9008142190	1
9007853627	2	9008142190	2
null	null	9008142190	4
null	null	9008142190	5