企业官网建设流程全解析

Visual Basic .NET 数据访问全解析

1. 代码初体验

在开发过程中，有时会遇到像下面这样的代码：

“l_Country OR @Original_Country IS NULL AND Country IS NULL) AND (Fax = @Origin al” & _ “_Fax OR @Original_Fax IS NULL AND Fax IS NULL) AND (Phone = @Original_Phone OR @” & _ “Original_Phone IS NULL AND Phone IS NULL) AND (PostalCode = @Original_PostalCo de” & _ “ OR @Original_PostalCode IS NULL AND PostalCode IS NULL) AND (Region = @Origin al” & _ “_Region OR @Original_Region IS NULL AND Region IS NULL); SELECT CustomerID, Co mp” & _ “anyName, ContactName, ContactTitle, Address, City, Region, PostalCode, Country , “ & _ “Phone, Fax FROM Customers WHERE (CustomerID = @CustomerID)”

这段代码看起来很复杂，在 Visual FoxPro 中，我们可能不用了解实现细节就能让程序运