SQL Server 2012中加入兩個表中的列到一個

Question

我在不同的地方

兩個表

最終結果必須是

VendorName InvoiceNumber InvoiceTotal 

VendorName是表稱爲Vendors

InvoiceNumber和InvoiceTotal是在一張叫Invoices

它需要顯示所有的v結果即使供應商沒有任何發票，也會顯示最大的發票總計第一個DESC並按字母順序排列供應商名稱。

我試圖發票加入到我的

SELECT VendorName FROM Vendors 

，但我想不通的語法：/

Answer 1

使用LEFT JOIN包括那些廠商沒有發票，像這樣：

SELECT 
    v.VendorName, i.InvoiceNumber, i.InvoiceTotal 
FROM Vendors v 
LEFT JOIN Invoices i ON v.Id = i.VendorID 
ORDER BY i.InvoiceTotal DESC, v.VendorName ASC 

Answer 2

你的意思是類似於：

select VendorName 
     ,Count(InvoiceAmount) As InvoiceNumber 
     ,Sum(InvoiceAmount) As InvoiceTotal 
    from Vendor 
    left join Invoices on Vendor.VendorId = Invoices.VendorId 
group by VendorName 
order by 3 Desc 

Answer 3

您將希望使用LEFT JOIN來連接與兩個表相關的列上的兩個表。使用LEFT JOIN將返回所有vendors，即使他們沒有在invoices表中的條目：

select v.vendorname, 
    i.invoicenumber, 
    i.invoicetotal 
from vendors v 
left join invoices i 
    on v.vendorid = i.vendorid -- this is the column relating the two tables 
order by i.invoicetotal DESC, v.vendorname ASC 

如果您需要幫助學習JOIN語法，這裏是一個偉大的visual explanation of joins

Answer 4

你需要一個OUTER JOIN 。假設PK/FK是VendorID：

SELECT v.VendorName, i.InvoiceNumber, i.InvoiceTotal 
FROM Vendors v 
LEFT OUTER JOIN Invoices i ON v.VendorID = i.VendorID 
ORDER BY v.VendorName ASC 
     , i.InvoiceTotal DESC 

Answer 5

嘗試：

SELECT Vendors.VendorName, Invoices.InvoiceNumber, Invoices.InvoiceTotal 
FROM Vendors LEFT JOIN Vendors.VendorID on Invoices.VendorId 
ORDER BY Invoices.InvoiceTotal DESC 

你想讓你的ventors被全部組合在一起，或可以在供應商是在結果多於1次？您可以使用SUM（Invoices.InvoiceTotal）進行比賽以獲取InvoiceTotals的總數。