SQL Server 2019

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CREATE TABLE TableA (
  a INTEGER,
  b INTEGER
);

INSERT INTO TableA
  (a, b)
VALUES
  ('1', '2'),
  ('3', '4');

CREATE TABLE TableB (
  c INTEGER,
  d INTEGER,
  e INTEGER
);

INSERT INTO TableB
  (c, d, e)
VALUES
  ('5', '6', '7');
3 rows affected

ALTER TABLE TableA ADD c INTEGER;
ALTER TABLE TableA ADD d INTEGER;
ALTER TABLE TableA ADD e INTEGER;
UPDATE a
SET a.c = b.c, a.d = b.d, a.e = b.e
FROM TableA a CROSS JOIN TableB b;
2 rows affected

SELECT * FROM TableA;


a
b
c
d
e


1
2
5
6
7

3
4
5
6
7