Hi everyone,
I have a simple question.I have the following code written.It is a simple registration form.Now how can I verify the email already exists in the database through the code?
I used do-loop in asp classic but in .net I dhave no idea.!!!


<script runat="server" language="vb">
sub insertdata(sender as object,e as eventargs)
dim strconnection as string="server=(local);database=Test;integrated security=true;"
dim objconnection as new sqlconnection(strconnection)

dim strsql as string="insert into Register(Name,Family,Tel,email,Password,Confirmpas sword)" & _
"values (@Name,@Family,@Tel,@email,@Password,@Confirmpassw ord);"
dim objcommand as new sqlcommand(strsql,objconnection)
objcommand.parameters.add("@name",sqldbtype.nvarch ar)
objcommand.parameters.add("@Family",sqldbtype.nvar char)
objcommand.parameters.add("@Tel",sqldbtype.nvarcha r)
objcommand.parameters.add("@email",sqldbtype.nvarc har)
objcommand.parameters.add("@Password",sqldbtype.nv archar)
objcommand.parameters.add("@Confirmpassword",sqldb type.nvarchar)
objcommand.parameters("@name").value=txtname.text
objcommand.parameters("@Family").value=txtfamily.t ext
objcommand.parameters("@Tel").value=txttel.text
objcommand.parameters("@email").value=txtemail.tex t
objcommand.parameters("@Password").value=txtpasswo rd.text
objcommand.parameters("@Confirmpassword").value=tx tConfirm.text
objconnection.open()
objcommand.executenonquery()
objconnection.close()
end sub
</script>

Before adding txtEmail.text to SQLcommand just verify the entered text against DB like the following way

//Create function

CheckEmailAddress(txtEmail.text);

Function

public bool CheckEmailAddress(string strAddress)
{
bool Email;
//Enter SQL query like
string address = "select Emailaddress from Userprofile where Emailaddress ='" + strAddress + "';
if (address == strAddress)
{
return false;
}
else
{
return true;
}
}
-------------------------------

if (CheckEmailAddress(txtEmail.text)==true
{
//perform SQL transaction
}
else
{
//alert the user to enter another E-mail address
}