A
id username
1 aessjz
2 nature
B
uid uname INSERT INTO B
SELECT id,username FROM A WHERE id not in (2)
id username
1 aessjz
2 nature
B
uid uname INSERT INTO B
SELECT id,username FROM A WHERE id not in (2)
id username
1 aessjz
2 nature
B
uid unameINSERT INTO B (uid, uname)
SELECT id,username FROM A WHERE id not in (2)
SELECT id,username FROM A WHERE id not in (2)