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所以这是一个类似于另一个我得到代码的学校问题：

USE AP

SELECT VendorName, FirstInvoiceDate, InvoiceTotal
FROM Invoices JOIN
  (SELECT VendorID, MIN(InvoiceDate) AS FirstInvoiceDate
   FROM Invoices
   GROUP BY VendorID) AS FirstInvoice
  ON (Invoices.VendorID = FirstInvoice.VendorID AND
      Invoices.InvoiceDate = FirstInvoice.FirstInvoiceDate)
JOIN Vendors
  ON Invoices.VendorID = Vendors.VendorID
ORDER BY VendorName, FirstInvoiceDate

我需要更改它以创建视图而不是派生表我想的更像

IF NOT EXISTS (SELECT * FROM sys.views
        Where name = ‘EarliestInvoiceandTotalVEW’)


CREATE View AS
Select VendorName, FirstInvoiceDate, InvoiceTotal
From Invoices JOIN
    (Create VIEW FirstInvoice AS
    SELECT VendorID, MIN(InvoiceDate) AS FirstInvoiceDate
    From Invoices
    Group By VendorID) As FirstInvoice
    ON (Invoices.VendorID = FirstInvoice.VendorID AND
      Invoices.InvoiceDate = FirstInvoice.FirstInvoiceDate)
JOIN Vendors
  ON Invoices.VendorID = Vendors.VendorID
ORDER BY VendorName, FirstInvoiceDate

这将使视图执行相同的操作并检查它是否存在，因此不会每次都重新创建/定义它。

感谢您对此的任何意见！

对于我直接从 SQL Server 中取出的格式，我深表歉意，它通常格式正确......

这就是我要工作的：

 USE AP
 Declare @Create1 varchar(8000)

IF EXISTS (SELECT * FROM sys.views Where sys.views.name = 'EarliestInvoiceandTotalVIEW')
    drop view EarliestInvoiceandTotalVIEW;

SET @CREATE1 = 'CREATE View EarliestInvoiceTotalVIEW AS 
Select VendorName, FirstInvoiceDate, InvoiceTotal
From Invoices JOIN
  (SELECT VendorID, MIN(InvoiceDate) AS FirstInvoiceDate
   FROM Invoices
   GROUP BY VendorID) AS FirstInvoice
  ON (Invoices.VendorID = FirstInvoice.VendorID AND
      Invoices.InvoiceDate = FirstInvoice.FirstInvoiceDate)
JOIN Vendors
  ON Invoices.VendorID = Vendors.VendorID'

Exec (@CREATE1)

我必须将 where 设置为 sys.views.name =... 并设置一个 exec 命令，以便创建视图“首先”运行。

4

2 回答 2

1
于 2013-08-18T19:16:29.710 回答
1

There are multiple ways to check if a view exists. However, often the approach is to delete a view if it exists and then recreate it:

IF EXISTS (SELECT * FROM sys.views Where name = ‘EarliestInvoiceandTotalVEW’)
    drop view EarliestInvoiceandTotalVEW;

Then, your create view statement has two flaws. First it is lacking a name. Second it has an embedded create view in it. You have to decide which one you want to create -- a view for the subquery or a view for the entire statement (it is not clear to me from the question which is the right approach).

于 2013-08-18T19:17:34.693 回答