Detta bör göra vad du behöver
INSERT INTO T_target
(ID,
project_No)
SELECT ID,
21
FROM T1
WHERE ID IS NOT NULL
UNION
SELECT ID,
21
FROM T2
WHERE ID IS NOT NULL
Detta bör göra vad du behöver
INSERT INTO T_target
(ID,
project_No)
SELECT ID,
21
FROM T1
WHERE ID IS NOT NULL
UNION
SELECT ID,
21
FROM T2
WHERE ID IS NOT NULL