Ligeira alteração na solução de Bruno
SELECT (SELECT COALESCE(max(id),0)+1 FROM table1),
@rownum:[email protected]+1 new_id
FROM
(SELECT @rownum:=0) r,
(SELECT 1 UNION ALL SELECT 2) t1,
(SELECT 1 UNION ALL SELECT 2) t2,
(SELECT 1 UNION ALL SELECT 2) t3,
(SELECT 1 UNION ALL SELECT 2) t4,
(SELECT 1 UNION ALL SELECT 2) t5,
(SELECT 1 UNION ALL SELECT 2) t6,
(SELECT 1 UNION ALL SELECT 2) t7
LIMIT 100
Ou outra versão sem as variáveis
SELECT (SELECT Coalesce(MAX(id), 0) + 1
FROM table1),
t1.n * 10 + t2.n + 1 AS new_id
FROM (SELECT 0 AS n UNION ALL
SELECT 1 UNION ALL
SELECT 2 UNION ALL
SELECT 3 UNION ALL
SELECT 4 UNION ALL
SELECT 5 UNION ALL
SELECT 6 UNION ALL
SELECT 7 UNION ALL
SELECT 8 UNION ALL
SELECT 9) t1,
(SELECT 0 AS n UNION ALL
SELECT 1 UNION ALL
SELECT 2 UNION ALL
SELECT 3 UNION ALL
SELECT 4 UNION ALL
SELECT 5 UNION ALL
SELECT 6 UNION ALL
SELECT 7 UNION ALL
SELECT 8 UNION ALL
SELECT 9) t2
ORDER BY new_id
