SQL統計1 12月的資料，沒有資料的月份顯示為0

1.利用臨時表補足資料（hana）

select a.datayear as datayear, a.datamonth as datamonth,sum(datanum) as datanum from 

(select year(gl_lz_xktz_ny) as datayear,month(gl_lz_xktz_ny) as datamonth,count(*) as datanum
from tablename
where year(gl_lz_xktz_ny) >= year(add_years(current_date,-1)) and  year(gl_lz_xktz_ny) <= year(current_date)
group by year(gl_lz_xktz_ny) , month(gl_lz_xktz_ny)  
union 
select year(add_years(current_date,-1)) as datayear, 1  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 2  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 3  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 4  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 5  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 6  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 7  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 8  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 9  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 10  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 11  as datamonth , 0  as datanum from dummy
union 
select year(add_years(current_date,-1)) as datayear, 12  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 1  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 2  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 3  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 4  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 5  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 6  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 7  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 8  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 9  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 10  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 11  as datamonth , 0  as datanum from dummy
union 
select year(current_date) as datayear, 12  as datamonth , 0  as datanum from dummy
)a group by a.datayear,a.datamonth 
order by a.datayear,a.datamonth

2.新建一張表，表中只有乙個字段，只有12行資料，即（1,2,3,4,5...12）,然後左鏈結需要統計的資料表。

3.利用case when else end 列舉：(月份顯示在表名上)(sql)

select 'title' as 'datatitle',

isnull(sum(case when month = '1' then thismonthpassnum else 0 end),0) as 'month1' ,
isnull(sum(case when month = '2' then thismonthpassnum else 0 end),0) as 'month2' ,
isnull(sum(case when month = '3' then thismonthpassnum else 0 end),0) as 'month3' ,
isnull(sum(case when month = '4' then thismonthpassnum else 0 end),0) as 'month4' ,
isnull(sum(case when month = '5' then thismonthpassnum else 0 end),0) as 'month5' ,
isnull(sum(case when month = '6' then thismonthpassnum else 0 end),0) as 'month6' ,
isnull(sum(case when month = '7' then thismonthpassnum else 0 end),0) as 'month7' ,
isnull(sum(case when month = '8' then thismonthpassnum else 0 end),0) as 'month8' ,
isnull(sum(case when month = '9' then thismonthpassnum else 0 end),0) as 'month9' ,
isnull(sum(case when month = '10' then thismonthpassnum else 0 end),0) as 'month10' ,
isnull(sum(case when month = '11' then thismonthpassnum else 0 end),0) as 'month11' ,
isnull(sum(case when month = '12' then thismonthpassnum else 0 end),0) as 'month12' 
from tablename

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