> ## Documentation Index
> Fetch the complete documentation index at: https://help.teable.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Conditional Rollup

> Calculate cross-table statistics with filter conditions and return one aggregated value.

Conditional Rollup filters matching records from a target table without creating a link relationship first, then calculates statistics on a selected field. It is useful for calculating counts, sums, averages, and other results based on field values in the current record.

## Use Cases

| Scenario                 | Good for                                                                  |
| ------------------------ | ------------------------------------------------------------------------- |
| Employee task statistics | Count in-progress tasks and completed tasks for an assignee               |
| Period sales statistics  | Calculate sales amount, order count, or average order value by date range |
| Duplicate data checks    | Count duplicate names, phone numbers, or IDs                              |
| Regional reports         | Aggregate business data by region, store, or channel                      |

## Procedure

<Steps>
  <Step title="Create a conditional rollup field">
    Click the `+` icon on the right side of a field name, choose **Conditional Rollup**, and enter a field title, such as "Total sales amount".
  </Step>

  <Step title="Choose the target table">
    In the target table dropdown, choose the table to query.
  </Step>

  <Step title="Configure the rollup field">
    Choose the field to calculate and confirm the field type.
  </Step>

  <Step title="Set filter conditions">
    Add filter conditions, choose the field, condition type, and comparison value. The comparison value can be a static value or a field from the current table.
  </Step>

  <Step title="Choose an aggregate function">
    Choose a calculation method based on the data type, such as original value, unique values, unique count, sum, count, average, maximum, or minimum.
  </Step>
</Steps>

## Scenario Practice

### Team Task Volume Statistics

**Tables**

* Tasks table
* Statistics table

A team admin needs to count tasks in different statuses for each employee, such as in-progress and completed tasks, to understand workload distribution and completion progress.

**In-progress tasks**

1. In the employee information table, create a Conditional Rollup field named "In-progress tasks"
2. Target table: Task assignments table
3. Rollup field: Task ID
4. Filter conditions:
   * Field: Assignee -> Condition: Equals -> Value: Employee field from the current table
   * Field: Task status -> Condition: Equals -> Value: "In progress"
5. Aggregate function: Count all

**Completed tasks**

1. Create another Conditional Rollup field named "Completed tasks"
2. Target table: Task assignments table
3. Rollup field: Task ID
4. Filter conditions:
   * Field: Assignee -> Condition: Equals -> Value: Employee field from the current table
   * Field: Task status -> Condition: Equals -> Value: "Completed"
5. Aggregate function: Count all

### Find Duplicate Values

**Tables**

* Customers table, with fields such as customer name and phone number

In the customers table, find duplicate customer names before merging customer profiles.

**Steps**

1. In the customers table, create a Conditional Rollup field named "Customer name duplicate count"
2. Target table: Customers table (this table)
3. Rollup field: Customer name
4. Filter condition:
   * Field: Customer name -> Condition: Equals -> Value: Customer name field from the current table
5. Aggregate function: Count all
6. Create a Formula field named "Duplicate flag"
7. Set the formula to `IF(Customer name duplicate count > 1, "Duplicate", BLANK())`

The customers table shows how many times each customer name appears and marks duplicate records with "Duplicate", so you can filter and handle them later.

## FAQ

<AccordionGroup>
  <Accordion title="What is the difference between Conditional Rollup and Conditional Lookup?">
    Conditional Rollup returns one calculated value, which works well for totals, counts, and averages. Conditional Lookup returns a list of matching raw values, which works well for viewing detail data.
  </Accordion>
</AccordionGroup>