将字符串数组转换为整数数组

I have the following SQL:

我有以下SQL：

SELECT * FROM (SELECT t.id, t.summary, null as worker, tt.worked from ticket t
INNER JOIN (SELECT ticket, sum(seconds_worked)/3600.0 as worked FROM ticket_time GROUP BY ticket) tt ON tt.ticket=t.id
UNION ALL 
SELECT ticket,null, tt.worker, sum(tt.seconds_worked)/3600.0 from ticket_time tt GROUP BY ticket,worker) as foo
WHERE id in ('9755, 9759') ORDER BY id
SELECT *