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Gravity Forms: Require Unique Values for Different Fields

An easy way to make sure the user enters unique values in each of the designated fields.

Last updated | Written by 63 Comments

  • December 5, 2022: Added support for requiring unique values in List field columns.

  • September 23, 2022: Added support for case-insensitive comparisons when evaluating whether values are unique.

  • September 14, 2021: Migrated snippet to the Snippet Library.

  • January 11, 2020: Added support for requiring unique filenames in File Upload fields (single files only).

  • November 18, 2019: Added support for experimental "mode" parameter. Defaults to "collective". Also accepts "individual" to require each value to be unique when validating a multi-value field.

  • December 10, 2018: Fixed issue when comparing values of Checkbox fields (and other multi-input field types).

  • October 28, 2017: Added support for new parameter "validate_all_fields". Will force the "master" field to be validated along with any other fields in the validation group.

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gw-gravity-forms-require-unique-values

Have you ever needed to collect a personal phone number and an emergency phone number? Or maybe you need to collect a minor’s email address and also their parent/guardian’s email address? It’s important for these values to be unique. You don’t want users entering the same phone number or email address for both fields.

This snippet allows you to require the user to enter a unique value in each of the designated fields. You can specify multiple “groups” of fields

Getting Started

  1. Check requirements

  2. Install the snippet

    • Copy and paste the entire snippet into your theme’s functions.php file.

  3. Configure the snippet

    • Enter your form ID for the form_id parameter.
    • Enter each field ID that should be unique for the field_ids parameter. These field IDs should be passed as an array.
    • For more details on available parameters, see below.

Usage Examples

Add a Custom Validation Message

new GW_Require_Unique_Values( array(
	'form_id'            => 12,
	'field_ids'          => array( 14, 15 ),
	'validation_message' => 'My custom validation message!'
) );

Create Multiple Unique “Groups” on the Same Form

new GW_Require_Unique_Values( array(
	'form_id'   => 2,
	'field_ids' => array( 4, 5 )
) );

new GW_Require_Unique_Values( array(
	'form_id'   => 2,
	'field_ids' => array( 7, 8 )
) );

On some forms you may have multiple groups of fields that should be unique (i.e. two sets of phone number fields and two sets of email fields). You can create multiple instances of this snippet to create multiple unique groups.

Require Unique Field Compared Against ALL Form Fields

new GW_Require_Unique_Values( array(
	'form_id'   => 2,
	'field_ids' => array( 7 )
) );

In some cases, you may want a field on the form to be completely unique from any other field on the form. Rather than specifying all field IDs, you can simply specify the single field ID that should be unique.

Require Unique Values in List Field Columns

new GW_Require_Unique_Values( array(
	'form_id'   => 2,
	'field_ids' => array( 9 )
) );

If you specify a single field ID and that field is a List field, this snippet will automatically require that all columns contain unique values. For example, if two rows had the value “Bilbo Baggins” in the first column, a validation error would be returned.

Parameters

  • form_id (int) (required)

    The form ID of your form.

  • field_ids (array) (required)

    An array of fields IDs that should be unique.

  • validation_message (string) (optional)

    The message that is displayed if the field values are not unique. Defaults to: 'Please enter a unique value.'.

  • validate_all_fields (bool) (optional)

    By default, the first field ID in the “field_ids” array is used as the “master” value and not validated. Enable this option to validate the the first field ID as well. Defaults to false.

  • case_sensitive (bool) (optional)

    Indicate whether the unique value comparison should be case-sensitive. Defaults to false.

How’d we do?

We’d love to hear what you think of this snippet. Did you run into any issues installing it? Let us know in the comments below.

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Comments

  1. oliver blaum says

    hello,

    this is exactly what i need. but it does not work under gravity form 2.5.x – do you have an update on this?

    thanks oli

    Reply

    • Dario Space says

      Hi Oliver,

      It seems to be working on our end with Gravity Forms 2.5.

      If you are a Gravity Perks customer, drop us a line and we’ll be happy to dig into this.

    • oliver blaum says

      sorry, i now found the configuration part on the bottom (was confused with the value part on top.

      thanks for providing this code!

      oli

  2. Cameron Underdown says

    Does this snippet work with List fields? I’ve tried to install on a list field, but it didn’t seem to work.

    Reply

    • Ryan Donovan says

      Hey Cameron, This should work. Could you submit a ticket to our support channel with your use case and form and we would be more than happy to take a look into this for you.

  4. Jeen Kersten says

    Hello David,

    Is it also possible to get a validation against another form?

    We have form 1 with field 1 and form 2 with field 1

    The value of form 1 field 1 can’t already have a submission at form 2 in field 1.

    Greetings Jeen

    Reply

    • Ryan Donovan says

      Hello Jeen, While looking into this it does not look like we have a ready-made solution for this as it would require a custom snippet. Will note this as a possible addition to this snippet in the future. Thank you.

  5. STEPMaths says

    Thanks so much for this! I would love it if you could create a plugin that does this.

    In case you can’t, how do we make this work for several forms? Can we just separate the different form IDs with commas?

    Or do we need to copy and paste all of the code? Thanks!

    Reply

    • Ryan Donovan says

      Hello, Of course we can take this as a feature request and possibly build this in the future. 😀 As for adding this snippet to several of your forms, this tutorial may help with that!

  6. Kathi Watts says

    We used the code for Create Multiple Unique “Groups” on the Same Form and it works great, however we have a multiple selection field that we want to be unique. For instance, a person enters their country in Field 1 and in Field 2 they enter all of the countries they will be traveling to. We don’t want them to be able to add their own country in Field 2. With the code you provided it works great, but only if they select their own country by itself. If they select multiple countries and it includes their own, then it doesn’t work. Any suggestions?

    Reply

    • David Smith says

      Hi Kathi, thanks for being a Gravity Perks customer and submitting a support request. We’ll be in touch soon. 🙂

  7. Michael says

    Could this be modified to compare the values in a list: Say something like NET and GROSS where NET must be less than or equal to GROSS.

    Reply

  10. Mostafa says

    Hi David! i have two drop down list with same value. i want to no duplicate in second drop down it means: drop down list one have value: AAA then user cant select AAA in second drop down list. can you help me? thanks

    Reply

    • David Smith says

      This snippet would prevent the user from successfully submitting the form with the same option selected in both but it would not automatically remove or disable the the choice in the second field.

    • Mostafa says

      No i dont want remove my two drop box first for Nationality and second for citizenship. i want if user select Italy for Nationality cant select Italy for Second Citizenship. do you help me for solve this? Thanks

  11. Gert-Jan Buth says

    Hi,

    Has this snippet already been updated to work with GF 2.4? If not, when do you expect this update to come? Previously I had an issue with the Limitation snippet at this point, so this time I check first, to prevent a breakdown of the form…

    Reply

    • David Smith says

      This snippet has not be tested with GF 2.4; however, I don’t see any obvious conflicts. Let us know how it goes. ?

    • Gert-Jan Buth says

      Right now it looks like it does not work, but I’m not sure if this is because of ‘GF 2.4’, or because I apply it to two checkbox fields on which also the ‘Limit Checkboxes’ snippet is being applied.

  14. Scot MacDonald says

    David

    I need to make sure all field selections in a form are unique. How might that work in the snippet?

    Thanks

    Reply

    • David Smith says

      Unique to each other? Or unique to themselves across previously submitted values for the respective field? If the former, just include all the field IDs on your form in the field_ids parameter. If the latter, enable No Duplicates via the field settings for each field.

  16. Alex says

    Hello. I am trying to have something similar on a website, but I’m quite the noob when it comes to php and mysql queries… I rely mostly on plugins, but I can’t find anything that can help my case. I have a feeling that this code can be tweaked somehow to fit my scenario. Basically, what I need is to have some values into a database (like a series of random numbers) and a frontend form where a user can input a number. That number must be one from that database, else he would get a “wrong code” message. So it all comes down to cross-checking the user input with the values in the mysql database. I don’t know if I can do something like this with Gravity Forms – maybe with logical condition, but if there are thousands of numbers it would be insane to add condition for each…

    Can you please help me with this? Thank you!

    Reply

  17. Cedric says

    Not sure if I am looking in the right place…. but.

    We love Gravity Forms!

    Is there a way to make the Advanced “Address” Field unique?

    Thanks! Cedric

    Reply

  19. Erin says

    This is exactly what I needed! Thank you so much for all of the great work that you do, and all that you share freely. I am hoping to purchase your Gravity Perks plugin in the next few days!

    Reply

  20. Valérie says

    Hi David,

    I have used this code to compare two fields but I have a problem wtih the form_id which seems to not be recognized. It seems to be applied in all forms and not only the one selected.

    I have changed the id to test. My form_id is 8. http://comitedesfetesdesmanoreys.fr/fete-du-pays/formulaire-dinscription-fete-du-pays/

    new GW_Require_Unique_Values( array( 'form_id' => 12, 'field_ids' => array( 66, 53 ), 'validation_message' => __( 'Attention le nombre de viandes ne correspond pas au nombre d\'adultes inscrits !' ) ) );

    new GW_Require_Unique_Values( array( 'form_id' => 12, 'field_ids' => array( 66, 63 ), 'validation_message' => __( 'Attention le nombre de desserts ne correspond pas au nombre d\'adultes inscrits !' ) ) );

    new GW_Require_Unique_Values( array( 'form_id' => 12, 'field_ids' => array( 67, 73 ), 'validation_message' => __( 'Attention le nombre de viandes ne correspond pas au nombre d\'enfants inscrits !' ) ) );

    new GW_Require_Unique_Values( array( 'form_id' => 12, 'field_ids' => array( 67, 74 ), 'validation_message' => __( 'Attention le nombre de desserts ne correspond pas au nombre d\'enfants inscrits !' ) ) );

    Thanks for your help.

    Valérie

    Reply

    • Valérie says

      Hi David,

      I’ve succeeded to resolve my problem adding this function :

      public function is_applicable_form( $form_id ) { return $this->_args['form_id'] == $form_id; }

      and modifying the validate function like this :

      public function validate( $result, $value, $form, $field ) {

          if ( ! $this->is_applicable_form( $form['id'] ) || ! $this->is_applicable_field( $field ) ) {
        return $result;
    }</code>

      Valérie

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Gravity Forms: Require Unique Values for Different Fields

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