SQL：按连续日期计算记录数，即使某个日期不存在记录

Question

我正在使用SQL Server 2008 R2。

我在查询一张医院预约插槽表，并试图返回特定医生有多少预约插槽的列表被标记为预订，按周/年编组。

有些星期没有任何预约约会，但我希望结果列出所有即将到来的星期，即使预约的预约时间段数为零。

我要找的输出是沿着这些线路：

------------------------------------------- 
Year | Week Number | Number of Booked Slots 
------------------------------------------- 
2017 |  48  |  10    
2017 |  49  |   0 
2017 |  50  |   4 
2017 |  51  |   2 
2017 |  52  |   0 
2018 |  1  |   5 

我明白，一个标准选择综合这些结果将不会显示那些星期那里有一个记录计数为零，因为没有什么返回 - 所以我试图通过使用cte来首先产生所有即将到来的几周的列表。

然而，几经努力我可能，我不能得到查询显示零周...

我已经看到了一些类似的问题本解决方案，但尽管我尝试避风港” （包括SQL Count to include zero values）

这是我迄今为止编写的查询的最新版本。

WITH CTE_Dates AS 
    (
    SELECT DISTINCT Slot_Start_Date AS cte_date 
    FROM [Outpatients.vw_OP_Clinic_Slots WITH (NOLOCK) 
    ) 

SELECT 
    DATEPART(year,OPCS.Slot_Start_Date) [Year] 
    ,DATEPART(week,OPCS.Slot_Start_Date) [Week Number] 
    ,count(OPCS.Slot_Start_Date) [Number of Booked Slots] 

FROM 
    Outpatients.vw_OP_Clinic_Slots OPCS WITH (NOLOCK) 
    LEFT OUTER JOIN CTE_Dates ON OPCS.Slot_Start_Date=CTE_Dates.cte_date 
    LEFT OUTER JOIN Outpatients.vw_OP_Clinics CLIN ON OPCS.Clinic_Code=CLIN.Clinic_Code 

WHERE 
    OPCS.Slot_Start_Date >= '14/08/2017' 
    AND OPCS.Booked_Flag = 'Y' 
    AND CLIN.Lead_Healthcare_Professional_Name = 'Dr X' 

GROUP BY 
    DATEPART(year,OPCS.Slot_Start_Date) 
    ,DATEPART(week,OPCS.Slot_Start_Date) 

ORDER BY 
    DATEPART(year,OPCS.Slot_Start_Date)asc 
    ,DATEPART(week,OPCS.Slot_Start_Date)asc 

它返回的结果是正确的，但我只是需要它包括那些星期在计数为零的列表中。

请任何人都可以解释我要去哪里错了？我猜测我没有正确加入cte，但是我已经尝试了右侧和左侧连接，它们会产生相同的结果。我也试着通过swopping上面的查询语句和cte来反转查询，但是这也不起作用。

欣赏任何人可以建议的指导。

Answer 1

只是RIGHT JOIN@ListOfWeeks表的结果集您有：

DECLARE @ListOfWeeks TABLE ([Week_No] int, [Year_Number] int); 

DECLARE @i tinyint = 1, @y int = 2010; 

WHILE @i <= 52 AND @y < 2018 
BEGIN 
    INSERT INTO @ListOfWeeks([Week_No], [Year_Number]) VALUES (@i, @y); 

    IF @i = 52 BEGIN 
     SET @i = 0 
     SET @y +=1 
     END 
    SET @i += 1 
END 

SELECT * FROM @ListOfWeeks 

WITH [Your_Part] AS(
SELECT 
    DATEPART(year,OPCS.Slot_Start_Date) [Year] 
    ,DATEPART(week,OPCS.Slot_Start_Date) [Week Number] 
    ,count(OPCS.Slot_Start_Date) [Number of Booked Slots] 

FROM 
    Outpatients.vw_OP_Clinic_Slots OPCS WITH (NOLOCK) 
    LEFT OUTER JOIN CTE_Dates ON OPCS.Slot_Start_Date=CTE_Dates.cte_date 
    LEFT OUTER JOIN Outpatients.vw_OP_Clinics CLIN ON OPCS.Clinic_Code=CLIN.Clinic_Code 

WHERE 
    OPCS.Slot_Start_Date >= '14/08/2017' 
    AND OPCS.Booked_Flag = 'Y' 
    AND CLIN.Lead_Healthcare_Professional_Name = 'Dr X' 

GROUP BY 
    DATEPART(year,OPCS.Slot_Start_Date) 
    ,DATEPART(week,OPCS.Slot_Start_Date) 
), 
SELECT xxx.[Year_Number], xxx.[Week_No], yp.[Number of Booked Slots] 
FROM [Your_Part] yp 
RIGHT JOIN @ListOfWeeks xxx ON yp.[Year] = xxx.[Year_Number] AND yp.[Week Number] = xxx.[Week_No] 

Answer 2

IF OBJECT_ID(N'tempdb..##cal_weeks_temp', N'U') IS NOT NULL 
DROP TABLE ##cal_weeks_temp; 
create table ##cal_weeks_temp (date_of_week date, week_num int) 
declare @start_date date 
declare @end_date date 
set @start_date='01/01/2017' 
set @end_date='12/31/2018' 
while @start_date<@end_date 
begin 
    set @start_date=dateadd(day,1,@start_date) 
    insert into ##cal_weeks_temp values (@start_date,DATEPART(week,@start_date)) 
end 
select YEAR(t1.date_of_week) 'YEAR',t1.week_num, 
sum(case convert(varchar,t2.BookedTime,105) when convert(varchar,t1.date_of_week,105) then 1 else 0 end) 'count' 
from ##cal_weeks_temp t1 
left join Your_Table t2 
on convert(varchar,t2.BookedTime,105)=convert(varchar,t1.date_of_week,105) 
group by YEAR(t1.date_of_week) ,t1.week_num 
order by YEAR(t1.date_of_week) ,t1.week_num