这句代码有问题select * from score s1 join score s2,score s3,score s4,score s5 on s1.s_id=s2.s_id=s3.s_id=s4.s_id=s5.s_id where s1.c_id=1 and s2.c_id =2 and s3.s_id=3 and s4.s_id=4 and s5.s_id=5;

是的，这句代码有问题。在这个查询中，使用了多个JOIN子句来连接score表本身的多个实例，但是JOIN子句的连接条件被写成了连续的等号，这样的语法是不正确的。正确的写法应该是使用AND或OR来连接多个等式条件。同时，使用JOIN子句连接多个实例时，应该使用不同的别名来标识它们，以避免重名的冲突。修正后的查询语句应该是：

select *
from score s1
join score s2 on s1.s_id = s2.s_id
join score s3 on s1.s_id = s3.s_id
join score s4 on s1.s_id = s4.s_id
join score s5 on s1.s_id = s5.s_id
where s1.c_id = 1 and s2.c_id = 2 and s3.s_id = 3 and s4.s_id = 4 and s5.s_id = 5;