SQL Server 2017

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SELECT 1 AS id
INTO src_table
UNION ALL SELECT 2
UNION ALL SELECT 3
3 rows affected

CREATE TABLE tab_map(id_old INT PRIMARY KEY, guid UNIQUEIDENTIFIER);

INSERT INTO tab_map(id_old, guid)
SELECT id, NEWID()
FROM src_table;
3 rows affected

SELECT * FROM tab_map


id_old
guid


1
8a87bdac-b927-44d5-bf50-0f2903d45f0f

2
b1fe9e32-7990-427e-95ae-03685b04a194

3
fa488792-9632-4052-b48f-8ab35516e10c

id_old	guid
1	8a87bdac-b927-44d5-bf50-0f2903d45f0f
2	b1fe9e32-7990-427e-95ae-03685b04a194
3	fa488792-9632-4052-b48f-8ab35516e10c