Create a Unique Check

Step-by-step tutorial for creating a Unique check on a single field or a composite key. For what each property means and how the rule evaluates the data, see the How It Works page.

Permission Required

You need the Author team permission on the datastore to create an Active check, or Drafter to create it as a Draft. See the Permissions page for the full matrix.

Show me how

The app can walk you through this. Click Show me how in the check creation form's header, or press H while it is open, and the Add a Check walkthrough highlights each step while you fill in the real form.

Field reference

The Authored Check Details form is organized in the sections below. Fill them in as you follow the Steps.

Target

Field	Type	Description
Associate with a Check Template	Toggle	Links the check to a Check Template. Enabling it replaces the Rule Type dropdown with a Template dropdown where you pick an existing template, which then controls the check's properties. When off, you configure everything on this form.
Rule Type	Option	The validation logic to apply. Select Unique for this check. Shown only while Associate with a Check Template is off.
Table / File	Option	The table or file the check runs against. Locked after the check is saved.
Fields	Option	The field, or combination of fields, that must be unique. Select one field for a simple key, or two or more for a composite key, where uniqueness applies to the combination of values. Every field type is accepted.
Filter Clause	Text	A SQL `WHERE` expression that limits the rows the check evaluates. Rows outside the filter are ignored entirely.
Custom Anomaly Description	Toggle	Has no effect on this rule. The option replaces the message on Record Anomalies, and Unique emits a Shape Anomaly only.

Properties

Field	Required	Type	Description
Array Element Context		Toggle	Evaluates uniqueness across the elements of an array field instead of the array as a whole. Only relevant when the selected field is an array.

Pass Criteria

Field	Required	Type	Description
Coverage		Slider	The percentage of evaluated rows that must pass. Defaults to 100%; lower it only when a known fraction of rows is allowed to fail.

Ownership

Field	Required	Type	Description
Owner		Option	The user responsible for the check. Already filled in with the check creator.
Anomaly Assignee		Option	The user automatically assigned to anomalies the check produces.

Metadata

Field	Type	Description
Description	Text	A plain-language description of what the check enforces. Supports Markdown formatting: click the field to open the Markdown editor. Click the Apply suggested description button for a suggestion based on the rule type.
Tags	Option	Tags applied to the check for filtering and organization.
Additional Metadata	Key-value	Custom key-value pairs, typically links to catalog entries, tickets, or governance records.

Let AgentQ fill in the form

When AgentQ is configured for your deployment, the Check Assistant panel in the check form can author the check for you: describe the rule in plain language (for example, "order id must be unique in the orders table") and it proposes a configuration you can apply to the form. Review the filled-in fields, then Validate and Save as usual.

Steps

Each field is described in the Field reference above.

Step 1: Select the source datastore from the left menu, then click the Checks tab.

Step 2: Click Add in the top-right corner and select Check from the dropdown. The Authored Check Details form opens.

Step 3: Select Unique in the Rule Type dropdown.

Step 4: Fill in the remaining Target fields: the table or file, the Fields that must be unique, and, optionally, a Filter Clause.

Step 5: Leave Properties alone unless the selected field is an array, in which case set Array Element Context.

Step 6: Fill in the Pass Criteria, Ownership, and Metadata sections. Only the Description is required.

Step 7: Click Validate to test the rule against the selected data without saving it. A success message confirms the rule can run on that data. If validation fails, see Troubleshooting.

Step 8: Click Save. A success message confirms that the check was created.