IBuySpy Store购物例子中注册时的疑问？是在哪一步验证同名email是否存在

[enlyse]

提交信息中如果email已经有了，则会注册失败提示：Registration failed: That email address is already registered.

但我看不清楚程序是在哪一步验证同名email是否已经存在的？谁能告诉我？

在AddCustomer中没看到哪句是验证重名的，存储过程也看不出。。

**************************
//RegisterBtn_Click是报单提交处理函数
private void RegisterBtn_Click(object sender, System.Web.UI.ImageClickEventArgs e) {
// Only attempt a login if all form fields on the page are valid
if (Page.IsValid == true) {

// Store off old temporary shopping cart ID
IBuySpy.ShoppingCartDB shoppingCart = new IBuySpy.ShoppingCartDB();
String tempCartId = shoppingCart.GetShoppingCartId();

// Add New Customer to CustomerDB database
IBuySpy.CustomersDB accountSystem = new IBuySpy.CustomersDB();
String customerId = accountSystem.AddCustomer(Name.Text, Email.Text, Password.Text);//此处添加新用户

if (customerId != "") {

// Set the user's authentication name to the customerId
FormsAuthentication.SetAuthCookie(customerId, false);

// Migrate any existing shopping cart items into the permanent shopping cart
shoppingCart.MigrateCart(tempCartId, customerId);

// Store the user's fullname in a cookie for personalization purposes
Response.Cookies["IBuySpy_FullName"].Value = Server.HtmlEncode(Name.Text);

// Redirect browser back to shopping cart page
Response.Redirect("ShoppingCart.aspx");
}
else {
MyError.Text = "Registration failed: That email address is already registered.";
}
}
}

//AddCustomer是添加用户函数
public String AddCustomer(string fullName, string email, string password)
{

// Create Instance of Connection and Command Object
SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
SqlCommand myCommand = new SqlCommand("CustomerAdd", myConnection);

// Mark the Command as a SPROC
myCommand.CommandType = CommandType.StoredProcedure;

// Add Parameters to SPROC
SqlParameter parameterFullName = new SqlParameter("@FullName", SqlDbType.NVarChar, 50);
parameterFullName.Value = fullName;
myCommand.Parameters.Add(parameterFullName);

SqlParameter parameterEmail = new SqlParameter("@Email", SqlDbType.NVarChar, 50);
parameterEmail.Value = email;
myCommand.Parameters.Add(parameterEmail);

SqlParameter parameterPassword = new SqlParameter("@Password", SqlDbType.NVarChar, 50);
parameterPassword.Value = password;
myCommand.Parameters.Add(parameterPassword);

SqlParameter parameterCustomerID = new SqlParameter("@CustomerID", SqlDbType.Int, 4);
parameterCustomerID.Direction = ParameterDirection.Output;
myCommand.Parameters.Add(parameterCustomerID);

try {
myConnection.Open();
myCommand.ExecuteNonQuery();
myConnection.Close();

// Calculate the CustomerID using Output Param from SPROC
int customerId = (int)parameterCustomerID.Value;

return customerId.ToString();
}
catch {
return String.Empty;
}
}

//添加用户调用的存储过程
CREATE Procedure CustomerAdd
(
@FullName nvarchar(50),
@Email nvarchar(50),
@Password nvarchar(50),
@CustomerID int OUTPUT
)
AS

INSERT INTO Customers
(
FullName,
EMailAddress,
Password
)

VALUES
(
@FullName,
@Email,
@Password
)

SELECT
@CustomerID = @@Identity

[老譚山菜]

帮你顶一下了

[xuu27]

没看过IBuySpy Store的源代码和数据库：
不过从程序的写法来看：
它判断customerId 是否= ""，
如果=""就是 That email address is already registered.";
而customerId 用依赖于Procedure CustomerAdd的
SELECT @CustomerID = @@Identity

这是提交记录字段添加列的Identity值，所以我猜测它：
Customers表的EMailAddress字段是否是属于唯一或没重复值的列？？？？

[enlyse]

yes，原来EMailAddress字段作了唯一性的约束～～