您要为每个字符创建一个单独的行。一种方法是生成所有字符，然后由它们聚合。这是一种方法：
select chr(chars.c + ascii('A')) as c,
sum(case when ascii(left(m.nome, 1)) = chars.c + ascii('A') then 1 else 0 end)
from generate_series(0, 25) as chars(c) cross join
merchant m
group by c;
编辑：
select chr(chars.c + ascii('A')) as c,
count(m.nome)
from generate_series(0, 25) as chars(c) left join
merchant m
on ascii(left(m.nome, 1)) = chars.c + ascii('A')
group by c;
602392714
清零编程群