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

# Lookup

> Lookup is similar to Excel's FILTER function — no formulas, no manual table relations, just filter conditions to find and reference data, with built-in aggregation.

**Lookup** is similar to Excel's `FILTER` function — no formulas, no manual table relations. Just set filter conditions to find and reference data, with built-in aggregation.

## Add a field

Click + on the right — pick **Lookup** under field types.

## Configuration

### Field to reference

Pick **the field to reference** — cross-table referencing is supported. Pick the **table** and the **field** within it.

### Filter conditions

Add multiple **filter conditions**. The operators (equals, not equals, contains, doesn't contain, is empty, is not empty) sit between a field from the **referenced table** (left) and a field from the **current table** or a literal string / option (right; when the left field is single-select).

You can require all conditions to match, or any of them.

### Aggregation

Pick an aggregation to compute over the matching records, then a **number format**.

| **Aggregation**         | **Description**                            | **Example use**                                                          |
| ----------------------- | ------------------------------------------ | ------------------------------------------------------------------------ |
| Original                | Reference column data directly             | With a filter, return the original value of records matching a condition |
| Deduplicated            | Remove duplicates                          | Strip duplicate records                                                  |
| Sum                     | Add up the original values                 | With a filter, see the sum of records matching a condition               |
| Average                 | Average of original values                 | With a filter, see the average of records matching a condition           |
| Max                     | Largest of original values                 | With a filter, see the max of records matching a condition               |
| Min                     | Smallest of original values                | With a filter, see the min of records matching a condition               |
| Count non-empty numbers | Count of non-empty numeric values          | Count non-empty numeric records                                          |
| Count non-empty values  | Count of non-empty values, numeric or text | Count non-empty records                                                  |
| Count distinct          | Count after deduplication                  | With a filter, count distinct categories matching a condition            |
| Row count               | Count of source records                    | With a filter, count records matching a condition                        |
| Concatenate as text     | Join displayed values with comma separator | Reference a multi-select and join its options into text                  |

Number formats: decimal places, percentage, thousands, currency, date, etc.

**Why "with a filter"?**

If you don't need a filter — just min / max / sum / count over a column — use the column's stat bar at the top instead.

# Common scenarios

## Look up a product code by name

Use the inventory table as the source, reference the product code, match on product name to find the corresponding code.

## Calculate sales per store

Use the order detail table as the source, reference pre-sale revenue, filter by category, and sum the revenue per category.

## FAQ

* **Q: Can a lookup field reference multiple fields?**

  A: No — one field per lookup. Add multiple lookup fields to reference different fields across different tables.
* **Q: What filter conditions are supported?**

  A: Currently equals / not equals / contains / is empty / is not empty / earlier than / later than (date fields only).
* **Q: How many filter conditions can I add?**

  A: Up to 5.
* **Q: Can I use lookup in AI Tables embedded in docs and sheets?**

  A: Yes. You can add multiple tables in a doc or sheet and look up across them.
* **Q: Which fields can be referenced or used as filters?**

  A: Every AI Table field type can be referenced — the lookup keeps the source's format. If the referenced field is a one-way or two-way link, linked records are deduplicated by default. Every field type can also serve as a filter.
* **Q: Can I look up hidden fields?**

  A: Yes — hidden fields appear in the dropdown of the lookup configuration; pick one to use as source or filter.
* **Q: Are lookup results live?**

  A: Yes. When the source data changes, the lookup updates automatically — no manual refresh.
* **Q: Can I look up across AI Tables?**

  A: Not yet. Lookup works within the same AI Table (or doc / sheet file).
* **Q: Why can't I edit a lookup field's value?**

  A: Lookup values are auto-generated from the source — edit them in the source table.