记录汇总统计的问题

[HBJMSHOP]

有表记录如下：

f_djh f_syybm ... ...
1420091011 0910
1420091011 0910
1420091013 0912
1420091013 0912
1420091014 0910
1420091014 0910
1420091014 0910
1420009101 0913

汇总后如下：

f_syybm(收银员编码) jl(笔数)
0910 2
0912 1
0913 1

[快乐_石头]

select f_syybm,
       count(*)JL
from tb group by f_syybm

[--小F--]

select  f_syybm,count(1) as jl from tb group by  f_syybm     

[SQL77]

select f_syybm,
       count(DISTINCT f_syybm )JL
from tb group by f_syybm

[--小F--]

为什么是
2
1
1
??

[SQL77]

select f_syybm,
       count(DISTINCT f_djh)JL
from tb group by f_syybm

[ncufunk]

SELECT 
F_SYYBM AS 收银员编码,SUM(F_DJH) AS 笔数
FROM TB
GROUP BY F_SYYBM
ORDER BY F_SYYBM

[ncufunk]

SELECT 
F_SYYBM AS 收银员编码,COUNT(*) AS 笔数
FROM TB
GROUP BY F_SYYBM
ORDER BY F_SYYBM

刚写错了。

[nianran520]

select f_syybm,count(distinct f_djh) as jl
from tb
group by f_syybm

[cencenshan]

[Quote=引用 4 楼 fredrickhu 的回复:]
为什么是
2
1
1
??
[/Quote]f_djh中相同项要使用distinct
select f_syybm,count(distinct f_djh) as jl
from tb
group by f_syybm