计算发票

Question

SELECT VendorState, VendorCity 
FROM Vendors JOIN COUNT(*)InvoiceDate as TotalInvoices ON Invoices 
WHERE VendorState = 'NV' AND 'MI' 

总数我上面不会在所有的工作的尝试：/我想把它从卖方表显示

VendorState如果状态是NV或MI

VendorCity

和TotalInvoices为每个城市和最终在总计绘制它从发票表InvoiceDate的计数

Answer 1

尝试

SELECT COUNT（InvoiceDate）为[NumberInvoices]，VendorState，VendorCity 从供应商处INNER JOIN发票ON 卖方PK * = 发票FK WHERE VendorState在（ 'NV'， 'MI'） 组由VendorState ，VendorCity

Answer 2

你不能以这种方式连接表。您需要在两个表之间共享一个共享的值，如供应商ID或其他内容。

因此，首先，它是：

select a.vendorstate, a.vendorcity, sum(invoices) as 'the sum' 
from vendors a inner join invoices b on a.vendorid = b.vendorid 
group by a.vendorstate, a.vendorcity 
where state in ('NV','MI') 

这类似于你的其他问题

Answer 3

你需要指定为了加入Vendors到Invoices在Invoices表的外键。这里有一个例子：

SELECT v.VendorState, v.VendorCity, COUNT(i.InvoiceDate) AS Invoices 
FROM Vendors v WITH(NOLOCK) 
JOIN Invoices i WITH(NOLOCK) ON i.VendorID = v.VendorID 
WHERE v.VendorState IN ('NV', 'MI') 
GROUP BY v.VendorState, v.VendorCity 
ORDER BY v.VendorState, v.VendorCity 

很显然，您需要更改加入i.VendorID = v.VendorID到任何按键应该在这里。