也许这是内部查询分配一个行号，外部查询计算出前两个月有多少未支付

drop table if exists t;
create table t(id int, dt date, dummy int);
insert into t values 
(1,'2018-01-31',1),(1,'2018-02-28',1),(1,'2018-03-31',1),
(2,'2018-01-31',0),(2,'2018-02-28',0),(2,'2018-03-31',1),
(3,'2018-01-31',1),(3,'2018-02-28',0),(3,'2018-03-31',1),
(4,'2018-01-31',0),(4,'2018-02-28',0),(4,'2018-03-31',0);

    select s.id,sum(dummy) cnt
from
(
select t.*,
        if (t.id <> @p,@r:=1,@r:=@r+1) r,
        @p:=t.id p
from t
cross join (select @r:=0,@p:=0) rn
order by t.id,t.dt
) s
where s.r <= 2 
group by s.id having cnt = 0;

+------+------+
| id   | cnt  |
+------+------+
|    2 |    0 |
|    4 |    0 |
+------+------+
2 rows in set (0.00 sec)