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I need help with CSS, Javascript, or jQuery.
What is a dedicated support manager?
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Is there an option to pay via invoice, check, wire transfer, or something other than a credit card?
Where can I find a copy of my receipt or invoice?
I'm over the storage limit for my account. How do I add more storage or get under the limit?
I'm over the record limit for my account. How do I add more records or get under the limit?
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Managing Apps
How do I remove the "Powered by Knack" logo at the bottom of my app?
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App Building
How do I find the most recent date from a connected object?
How do I move or copy fields or data from one object to another?
How do I add a logo to my app?
How can I change the color of something in my app?
The menu isn't showing for my app on mobile devices. How do I fix that?
How do I create a field that always shows today's date?
How do I show multiple dates on a calendar?
Is there a way to add a display rule to multiple columns at one time instead of having to update each column individually?
How can I show a customer's payment history if I'm collecting payments through my Knack app and through cash or check?
Can I combine two date fields into a single date field? For example, combining a start and end date into a single field?
Is it possible to display more than 100 records at a time on a table, list, or search view?
Is there a way to have new users be automatically logged-in after they register?
Do I need a separate user role object for my Vendors, Customers, Employees, Contacts, etc?
How do I create an "If, Then" or conditional equation?
Does Knack offer a service for building apps or have developers I can hire?
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Can I?
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Other
Does the signature captured through a signature field constitute a legally binding signature?
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How do I batch download all of the images and files In my app?
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Imports
Some of my fields aren't importing correctly. How can I fix that?
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My import is failing or getting stuck. What do I do?
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Can I import data into more than one object at the same time?
Can I undo or reverse an import?
I am importing data for the first time. How do I do that?
How do I update existing data using an import?
My import is taking a long time. Can you take a look?
I'm having trouble importing into a specific type of field. What can I do?
I'm getting an error when importing. What do I do?
Do the validation rules on fields trigger when importing data?
How To Guides
Users & Logins
Save a User's Payment Method
Force Users to Reset Their Passwords
Create a Single Login Page for Multiple User Roles
Show Records Connected To The Logged-in User's Company Or Other Group
Create an Admin User Role to View All Records
Add Read-Only Access For Users
Show Records Connected to the Logged-in User
Add Functionality to Your Live App
Manage Your Records
Use an Edit Form to Create Records If They Don't Exist
Use Zapier to Insert Connected Records
Copy a Record Using Record Rules
Create a Version History for Records
Track When Records are Created and Updated
Track Which User Last Updated a Record
Workflow & Automations
Add Stages to Your App
Using Mailchimp
Add Status Indicators to Your App
Add Assignments to Your App
Notify a User That an Item is Ready for Review
Create a Registration Form with Limited Availability
Add a Pipeline to Your App
Create a Button or Link that Updates a Field to a Custom Value
Add Notification & Reminder Emails to Your App
Approve New Records Before Displaying Them
Store Multiple Images or Files for Individual Records
Use Multiple Image Sources for a Single Image Field
Workflow Tools
Work with Connected Records
How to Show Multiple Fields in Your Connection Drop-Down
Showing Parent-Child Records in the Live App
Logic, Equations & Formulas
How to Display Multiple Date Formats Using a Single Date Field
How To Number Line Items
Show Upcoming Birthdays
How to Set a Random ID
Display a Message When a Deadline is Approaching
Generate Simple Numeric Barcodes Automatically
Calculate Age in Years from a Birthday
How to Extract the Start and End Dates from a Date Field
Start an Auto Increment Field from Any Number
Customize Views
How to Add Inline Editing to a Table
Create a Print-Friendly Invoice Page
How to Click on an Image to Go to Another Page
How to Add Connection Links to Views
How to Add a Map to a Details View
How to Add Groupings to a Table
Reports, Queries, and Summaries
App Walkthroughs
Build a Quiz App
Build an Inventory Manager App
Build an Orders App
Build a Warehouse Manager App
Build a Member Directory
Build a Map Directory or Store Locator App
Forms
Create a Multi-Part Form
How to Change the Layout of Forms
How to Add Instructions to a Form
How to Customize the Text on a Submit Button
How to Limit an Uploaded File’s Size
How to Automatically Capture a User’s Location on a Form
How to Allow Users to Add New Options in Forms
How to Use URL Variables to Pre-Populate a Form
Add Read-Only Fields to a Form
How to Create Dynamic Dropdowns in Forms
Manage Your Account
Table of Contents
- All Categories
- Builder Guide
- Fields
- Validation Rules
Validation Rules
Updated
by Danielle Kellogg
What is a Validation Rule?
Validation rules allow for values which are or are not allowed on a specific field. Validation rules apply when adding or editing a field, both in the Builder and on Live App pages, and appear as a message if the rule has not been met. For example, you can:
- Limit the number of characters in a paragraph text field
- Restrict files to specific types and sizes
- Allow only a specific range of numbers and dates
- Run your own regular expressions on a Short Text field
- Set password minimum and maximum character counts on a User Role password field
Manage Validation Rules
Add a Validation Rule
From the "Data" section in the Builder, select the object where the field is located, where you want to add your validation rule. In order to add a validation rule to a field, you'll need to edit that field. To do so, click on the gear icon on the field.
- Click on the Validation Rules tab from the Advanced Options modal.
- Check the checkbox next to "Add field validation rules" to start adding rules for this field.
- Add your When condition: a field on that object, the condition, and the value. Available conditions will depending on the type of the field chosen.
- Type the message you want to appear when the condition in the When section is not met.
- Click on the "Add Rule" button if you'd like to add additional validation rules for this field. See the section below Multiple Validation Rules for details on more than one validation rule on a field.
The above rule states that When this field's character count is higher than 500, we will display a custom message alerting the user has gone over that character count.
Edit a Validation Rule
From the Schema section in the Builder, select the object where the field is located, where you want to edit your validation rule.
Click the check list icon on the field where the validation rule is saved, and then click on the "Validation Rules" tab to edit those rules.
Delete a Validation Rule
From the Schema section in the Builder, select the object where the field is located with the validation rules. Click the check list icon on the field where the validation rule is saved, and then click on the "Validation Rules" tab to delete a rule.
Click the delete icon on an individual rules to delete the rule.
Uncheck the checkbox "Add field validation rules" to remove all validation rules from the field you are editing.
Multiple Validation Rules
You can add multiple validation rules to a single field to check for different conditions. If no conditions match (that is, if no rules are broken), the field will submit as usual:
When a validation rule finds a match, your user will be notified and the affected field will be highlighted:
Regular Expressions and Validations Rules
- Regular expressions, or regex, can also be used with validation rules to define the data that users enter. For example,
^[0-9]{8}$
can be used to require 8 numbers and^[A-Z]{3}$
can be used to require 3 uppercase letters. - While we are unable to troubleshoot custom regex, Rubular is a helpful regex editor to test regular expressions as you write them.
- Errors with a regular expression can result in a form that's stuck spinning, however, no error message is displayed. If you see this behavior and you're using regular expressions in your validation rules, please check to make sure there are no errors in the regex using Rubular mentioned above.
Notes & Troubleshooting
- Fields that have at least one validation rule applied will show with a check mark icon adjacent to the field name on the Builder fields page.
- Validation Rules only work for form submissions and inline edits.
- Fields that are included in validation rules must be on the view to be validated against.
- Imports, form rules, and batch updates do not perform validation checks.
- Validation rules do not check for case-sensitivity.