Question

我有一个存储发票详细信息的数据库。正如您所期望的那样，发票的每个细节都列在数据库中。一些样本信息：

Invoice#     Service_Type    Detail_Code
1234            1               AB
1234            2               DF
1234            5               ER
1235            1               AB
1236            1               AB
1236            2               DF
1237            1               AB
1238            1               AB
1239            1               AB
1239            3               DZ

我想写一个查询来计算客户服务类型为＆＃39; 1＆＃39;的服务数量。并且没有DZ或DF的详细代码。所以在这种情况下，我的查询结果将是：

"3"

它将计算发票号码：

1235
1237
1238

我完全没能做到。这是我的疑问：

SELECT Invoice_Number
FROM Invoice_Detail_Tb
WHERE (Invoice_Number IN (SELECT Invoice_Number
                          FROM Invoice_Detail_Tb AS Invoice_Detail_Tb_1
                          WHERE (Service_type = '1')
                            AND (Invoice_Date BETWEEN @startdate AND @enddate)
                            AND (Store_Number = @storenumber)))
  AND (Detail_Code NOT IN ('DF', 'DZ'))

当我运行此查询时，我不断得到＆＃34; 6＆＃34;这是service_Type＆＃34; 1＆＃34;的服务总数。我错过了什么？

Answer 1

一种方法是使用EXCEPT。

SELECT Invoice_Number
FROM  Invoice_Detail_Tb
where service_type = '1'
EXCEPT
SELECT Invoice_Number
FROM  Invoice_Detail_Tb
where Detail_Code IN ('DF', 'DZ')

由于您无法使用except，因此可以使用not exists。

SQL Fiddle

SELECT Invoice_Number --use count(*) if you only need count
FROM  Invoice_Detail_Tb t
where service_type = '1'
and not exists(select 1 from Invoice_Detail_Tb where invoice_number = t.invoice_number and
               Detail_Code IN ('DF', 'DZ'))

Answer 2

使用DISTINCT：

时，获取唯一发票号可能非常简单

SELECT DISTINCT
    Invoice_Number
FROM  Invoice_Detail_Tb
WHERE
    Service_type = '1'
    and Detail_Code NOT IN ('DF', 'DZ')
    and Invoice_Date BETWEEN @startdate AND @enddate 
    and Store_Number = @storenumber

对于计数服务：

SELECT 
    Invoice_Number,
    count(*) as services_Count
FROM  Invoice_Detail_Tb
WHERE
    Service_type = '1'
    and Detail_Code NOT IN ('DF', 'DZ')
    and Invoice_Date BETWEEN @startdate AND @enddate 
    and Store_Number = @storenumber
GROUP BY Invoice_Number

使用In从第二个查询中提取结果

2 个答案: