drop table if exists t1;
create table t1 (a int);
select count(a) as b from t1 where a=0 having b > 0;
b
insert into t1 values (null);
select count(a) as b from t1 where a=0 having b > 0;
b
select count(a) as b from t1 where a=0 having b >=0;
b
0
drop table t1;