create table t1
(
a int, b varchar(30),
primary key(a)
) engine = NDB;
insert into t1 values (1,'one');
insert into t1 values (2,'two');
insert into t1 values (3,'three');
insert into t1 values (4,'four');
#
# Group by query 1
#  - group by
#
select sum(a), 'b' from t1 where a > 0
and b is not null group by substr(b,2)
having sum(a) <> 2 ;
sum(a)	b
1	b
3	b
4	b
#
# Group by query 2
#  - union + group by
select sum(a) + 200 as the_sum, 'City 1' as the_town from t1
group by b
union distinct
select sum(a) + 200, 'City 2' from t1
group by b ;
the_sum	the_town
201	City 1
201	City 2
202	City 1
202	City 2
203	City 1
203	City 2
204	City 1
204	City 2
drop table t1;