query to select count of records for each year

问题

sorry for this newbie question ... im trying to get number of rows per year of my table..... this is my try:

select count(*)
from tbl_fact
where stat = 1 and id = 16
group by (year(fact_date))
go

and

select count(*)
from tbl_fact
where stat = 1 and id = 16 and year(fact_date) in (select Distinct(year(fact_date)) from tbl_fact)
group by (year(fact_date))
go

i have records that taged with dates that for now i have dates from 2017 and 2018 so i need counts for each year. but the id=16 has only date tag of 2018 not 2017 so i get result as

eg: 15

how ever it should be like

eg: 0 //2017
    15 //2018

回答1:

A simple method to get all years in the data -- even when they don't meet the conditions of the where clause -- is to use conditional aggregation:

select year(fact_date) as yyyy,
       sum(case when stat = 1 and id = 16 then 1 else 0 end) as cnt_16
from tbl_fact
group by year(fact_date)
order by yyyy;

回答2:

SELECT CAST([CountPerYear] AS VARCHAR(10)) 
        + ' // ' + 
        CAST([Year] AS VARCHAR(10))
FROM 
 (
    select   year(fact_date) [Year]
           , count(*)  [CountPerYear]
    from tbl_fact
    where stat = 1 and id = 16
    group by year(fact_date)
 )x

回答3:

You can get the count and year in two columns by:

select 
     count(*) as [COUNT], 
     year(fact_date) as [Year]
from tbl_fact
where stat = 1 and id = 16
group by (year(fact_date));

or as one string

select 
     count(*) + ' // ' + year(fact_date) as [grouping]
from tbl_fact
where stat = 1 and id = 16
group by (year(fact_date));

来源：https://stackoverflow.com/questions/48663898/query-to-select-count-of-records-for-each-year

标签

sql

sql-server

sql-server-2012