How to validate against duplicate email address

Hi,

I've searched the forums and found postings relating to using validation toolkit to check for duplicate email addresses in a database before adding a new record but I don't fully understand how to get it to work and I was hoping someone could explain it more clearly for me? I've listed the exact steps I need to create below.

1) Check the email address a user enters into a registration form against records in a database

2) If the email address is found in the database then the record is not inserted, instead a message is displayed stating that the email address is already registered

3) If the email address is not found then the record should be inserted into the database.

I know I need to create a recordset that is filtered by email address (check the database values against the value entered into the email field on the form), but I don't know how to specify the validation rule correctly - do I use Like Entry??

Also I should point out that I'm not using DataAssist to generate the insert record code - instead I'm just using Dreamweaver's built-in Insert Record behaviour.

Any help is appreciated.

First, you need to create the recordset to filter the email address column on the email address form element.

the recordset will create a variable named:
$totalRows_RecordsetName

(where RecordsetName is the name of the recordset) with the number of records returned.

the idea is to use numeric validation to make sure that recordset does not return any records (is empty)

add server validation, chose numeric validation and set the server variable to:
$totalRows_RecordsetName

Set the minimum number to -1 and the maximum number to 0.


to show the error message, use the validation show if behavior.

Thank you Jason, I will give it a go.

[Update] This is now working perfectly. Thank you for your very clear instructions Jason. Much appreciated.

glad to hear it is working.

Hi again,

I've moved my page over to a different server and now the validation isn't working. It states a duplicate email address is found even when one isn't. I've followed the instructions Jason posted earlier about 30 times and I just cannot see what I'm doing wrong or why it's not working.

If I remove the validation then the details entered in the form are added to my database, if I include the validation then they are never added, even when a completely new email address is used.

I've attached a the page as a zip file - any help is very much appreciated.

the problem was caused by the order of the code.

the code to create the recordset was after the code to perform the validation.

I am attaching an updated copy of the page with the code rearranged.

Brilliant! Thank you very much for your help Jason. It works perfectly now. I tried re-ordering the code myself before updating this thread and I couldn't get it to work. I'll use your version of the file as a reference in the future.

you're welcome.

Hi Jason:

I was reading your instructions on how to validate against email addresses. Your instructions look quite clear, except that when you say "add server validation, chose numeric validation and set the server variable to: $totalRows_RecordsetName" I don't know how to "add server validation".

Could you kindly explain a bit further? Just in case, attached you will find the "Enter Profile" page where I would like to add the email validation.

Thank you for your attention.

to add server validation, you need to add the Server Validation server behavior.

The steps for this depend on what tools you have installed.

if you have Validation Toolkit installed, go to Insert -> WebAssist -> Validation Toolkit -> Server Validation.


if you have either Form Toolkit or CSS Form Builder, Go to Webassist -> Forms -> Validation -> Server Validation