Question

如果找不到特定日期的记录，我正在尝试使此查询在“nb”字段中显示0。现在输出为0行，除非我指定的日期存在于“Commande”表中。

SELECT      
  isnull(COUNT(*), 0) as nb, 
  CONVERT(date, c.Date_commande) as Date_commande, 
  f.Code_fournis
FROM        Commande c
LEFT JOIN   Fournisseur f
ON          c.Code_fournis = f.Code_fournis
WHERE       f.Code_fournis = 'XNZ'
AND         Convert(date, c.Date_commande) = '2015-10-28'
GROUP BY    CONVERT(date, c.Date_commande), f.Code_fournis
ORDER BY    c.date_commande desc

Answer 1

The problem is you can't count what isn't there. You need create a table allDates for all the dates. 100 years mean 36,500 rows so is a small table. Use this one as example

How can I generate a temporary table filled with dates in SQL Server 2000?

Then

SELECT      
  isnull(COUNT(*), 0) as nb, 
  CONVERT(date, AD.date) as Date_commande, 
  f.Code_fournis
FROM        
            allDates AD
LEFT JOIN   Commande c
       ON   AD.date = CONVERT(date, c.Date_commande)
LEFT JOIN   Fournisseur f
       ON   c.Code_fournis = f.Code_fournis
WHERE       f.Code_fournis = 'XNZ'
AND         Convert(date, c.Date_commande) = '2015-10-28'
GROUP BY    CONVERT(date, AD.date), f.Code_fournis
ORDER BY    AD.date desc

Answer 2

因为Commande中不存在'2015-10-28'，您需要在虚拟表中为它创建一行：

SELECT      
  SUM(case when c.Date_commande is null then 0 else 1 end) as nb, 
  d.Date_commande as Date_commande, 
  f.Code_fournis
FROM (values(cast('20150101' as date), 'XNZ') as d(Date_commande, Code_fournis)      
LEFT JOIN Commande c on Cast(c.Date_commande as date) = d.Date_commande
LEFT JOIN   Fournisseur f
ON          c.Code_fournis = f.Code_fournis and f.Code_fournis = d.Code_fournis
GROUP BY    d.Date_commande, f.Code_fournis
ORDER BY    d.Date_commande desc

这也可行：

SELECT isnull(COUNT(*), 0) as nb, 
    CONVERT(date, c.Date_commande) as Date_commande, 
    f.Code_fournis
From your query
Union All
Select 0, '20150101', 'XNZ'
Where not exist (
    select 1 
    From Commande c
    LEFT JOIN   Fournisseur f
    ON c.Code_fournis = f.Code_fournis and  = d.Code_fournis
    Where f.Code_fournis = 'XNZ' 
        AND Convert(date, c.Date_commande) = '20150101'
 )

Answer 3

即使这是旧的并且有一些downvotes，我最近解决了我的问题。我不得不生成一个包含日期的表格。

SELECT      SUM(CONVERT(int, case(vtl.oeil) WHEN RTRIM('I') THEN 2 ELSE 1 END)) as nb, 
            CONVERT(date, c.Date_commande) as Date_commande,
            RTRIM(f.Code_fournis) AS Code_fournis
FROM        Commande c
LEFT JOIN   Fournisseur f
ON          c.Code_fournis = f.Code_fournis
WHERE       c.Code_fournis = 'XNZ'
AND         Convert(date, c.Date_commande)
BETWEEN     '2015-11-30'
AND         '2015-12-04'
GROUP BY    CONVERT(date, c.Date_commande), f.Code_fournis
UNION ALL
SELECT      '0', date, 'XNZ'
FROM        allDates
WHERE       date    
BETWEEN     '2015-11-30'
AND         '2015-12-04'
AND date NOT IN (
        SELECT      convert(date, c.Date_commande) as date
        FROM        allDates ad 
        INNER JOIN  Commande c 
        ON          ad.date = convert(date, c.Date_commande) 
        WHERE       c.Code_fournis = 'XNZ'
        and         convert(date, c.Date_commande) 
        BETWEEN     '2015-11-30'
        AND         '2015-12-04'
)
ORDER BY    c.date_commande asc

它与我要求的有点不同，但希望它可以帮助某人。

没有找到记录时，SQL server显示计数0

3 个答案: