# Find duplicate email on collection item entry **URL:** \ **Category:** Ask for Help\ **Created:** [March 19, 2024, 11:08am UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797 "2024-03-19T11:08:02Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Paradize](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/paradize/32/72367_2.png) [@Paradize](https://community.glideapps.com/u/Paradize)\ **Post date:** [March 19, 2024, 11:08am UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/1 "2024-03-19T11:08:02Z")
Hey, I have an onboarding flow where I will let let an agency add their clients. I would like to show them that it’s not possible to enter a certain email if it already exists. My problem is, is that I am doing this entry with a collection, this means, the row/value only gets added after submit. Is there a way to maybe trigger an action on submit to search if that email already exists and if yes, not submitting the form? I tried adding a relation to the email and then a rollup to cound how many times that email exists, but I’m stuck there. thank you so much 🙂 ---
**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\ **Post date:** [March 19, 2024, 11:22am UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/2 "2024-03-19T11:22:50Z")
> [@Paradize](#): > > Is there a way to maybe trigger an action on submit to search if that email already exists and if yes, not submitting the form? No, that’s not possible. > [@Paradize](#): > > I tried adding a relation to the email and then a rollup to cound how many times that email exists, but I’m stuck there. That’s the idea, but you need to use it with a Custom Form. [![](https://us1.discourse-cdn.com/flex002/uploads/glideapps/original/3X/4/5/45341fe992c2c539efb50c92c97c4dd9cd359718.jpeg "Helper Tables | Glide App Tutorial") ](https://www.youtube.com/watch?v=IlQnfK9sISk&t=94) ---
**Author:** ![Paradize](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/paradize/32/72367_2.png) [@Paradize](https://community.glideapps.com/u/Paradize)\ **Post date:** [March 19, 2024, 12:03pm UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/3 "2024-03-19T12:03:21Z")
Yes, I already have an onboarding helper table, but an agency can add multiple clients, so how can I add multiple users to that helper table? I have 1 row in the helper table and all user specific, so not really adding more rows. Can I add multiple values in one cell and then do the rollup with relation to the users table? ---
**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\ **Post date:** [March 19, 2024, 12:20pm UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/4 "2024-03-19T12:20:40Z")
The specific section of the video that I linked to talks about how to create a custom form. ---
**Author:** ![Paradize](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/paradize/32/72367_2.png) [@Paradize](https://community.glideapps.com/u/Paradize)\ **Post date:** [March 19, 2024, 12:23pm UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/5 "2024-03-19T12:23:13Z")
Yes, but does that mean I have to create another helper table, next to the onboarding helper table? ---
**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\ **Post date:** [March 19, 2024, 12:38pm UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/6 "2024-03-19T12:38:21Z")
Not necessarily. You just need to switch from using a native form to using a custom form. Where you collect the input values doesn’t matter. The main point is, when you use a custom form the input values will be written to user specific columns, so you can use them to create a relation to existing data, and then use the state of that relation to determine whether or not a duplicate is being created. You can then warn the user and stop them from submitting the form. ---
**Author:** ![Paradize](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/paradize/32/72367_2.png) [@Paradize](https://community.glideapps.com/u/Paradize)\ **Post date:** [March 19, 2024, 12:45pm UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/7 "2024-03-19T12:45:36Z")
Yes, that works, however I have: 1 agency → multiple clients In the onboarding flow the agency will add multiple clients. What is the easiest way to save the multiple creators in the helper table, if I have one row in the helper table with all user specific columns. Can I add an array or a list to one column/cell and populate it with more and more emails of the different clients added? ---
**Author:** ![Darren\_Murphy](https://sea2.discourse-cdn.com/flex002/user_avatar/community.glideapps.com/darren_murphy/32/47326_2.png) [@Darren\_Murphy](https://community.glideapps.com/u/Darren_Murphy)\ **Post date:** [March 19, 2024, 1:30pm UTC](https://community.glideapps.com/t/find-duplicate-email-on-collection-item-entry/71797/8 "2024-03-19T13:30:50Z")
How do they do it now? Presumably one by one? Is there any reason why they can’t continue to do that? Adding them as a batch is possible, but would require using the API.