Create a Field Count Check
Step-by-step tutorial for creating a Field Count check on a container. 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 | Required | 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 Field Count for this check. Shown only while Associate with a Check Template is off. | |
| Table / File | Option | The table or file whose field count is asserted. Locked after the check is saved. |
Properties
| Field | Required | Type | Description |
|---|---|---|---|
| Number of Fields | Number | The exact number of fields the container must hold. |
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 | Required | 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. |
Fields the form does not show
Field Count selects no columns and evaluates no rows, so the form offers no Field picker, no Filter Clause, no Coverage slider, and no Custom Anomaly Description toggle.
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, "the orders extract must always have nine columns") 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 Field Count in the Rule Type dropdown.
Step 4: Select the table or file whose shape you want to assert. Field Count has no Field picker, no Filter Clause, and no Coverage: the rule evaluates the container itself.
Step 5: Under Properties, set Number of Fields to the exact count the container must hold.
Step 6: Fill in the 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.