计算加入问题和答案表的记录

Question

我有两张桌子，想要解决问题：

表：问题

id   title  solved_answer_id
174  Title1 0
172  Title2 45
173  Title3 0
175  Title4 49 

表：答案

id  created_by question_id
49  953        175
47  907        173
48  906        173 
46  907        172
45  906        172

可能有人知道如何计算已解决的问题（solve_answer_id＆gt; 0）来回答created_by user：953？

谢谢！

P.S结果将是：1对于上述情况（solve_answer_id = 49）...

Answer 1

select count(q.id) as cnt
from questions q
join answers a on a.question_id = q.id
where q.solved_answer_id > 0
and a.created_by = 953