Lookup Field

Lookup fields are used to extract values from linked records and support aggregation calculations. They are the core field type for cross-table data linkage and summary analysis, usually used together with Link fields.

When to Use

• Display customer name in the Orders table (lookup from Customers table)
• Summarize the number of completed tasks linked to a project
• Calculate average supplier quote in the Products table
• Count total order amount for each customer in the Sales table

Creating a Lookup Field

1. Click Add Field in a table.
2. Select the Lookup field type.
3. Configure lookup parameters:
   • Source Table: Select the target data table that already has a link relationship.
   • Source Field: Select the field to extract.
   • Aggregation: Select original value, distinct, or aggregation mode.
   • Filter Conditions (optional): Only lookup linked records that meet the conditions.
4. Click Save.

Aggregation Modes

Mode	Description
Original	Directly display the target field value of linked records; shows as a list for one-to-many
Distinct	Display values after removing duplicates from multiple linked records
Distinct Count	Count of unique values after deduplication
Sum	Sum numeric field values
Count	Count the number of linked records
Average	Average numeric field values
Max	Maximum field value (supports numbers and dates)
Min	Minimum field value (supports numbers and dates)

Filter Conditions

Lookup fields support setting filter conditions on linked records:

• Supports multi-condition filtering by source table fields.
• Supports AND / OR combined logic.
• Supports 20+ operators (equals, not equals, contains, is empty, etc.).
• After setting filters, only linked records meeting the conditions participate in the calculation.

Field Formatting

For non-original/distinct modes, lookup fields support custom result formatting:

Format Type	Applicable Scenario
Number	Aggregation result is numeric; decimal places configurable
Currency	Display currency symbol, such as ¥
Percentage	Display as percentage
Date	For max/min date values; date format configurable

In original and distinct modes, lookup results follow the source field's original type rendering (such as thumbnails for attachments, avatars for members, colored tags for single/multi-select, etc.).

Preview

When configuring a lookup field, if the current record already has linked data, you can preview the calculation result in real time to verify the configuration.

Relationship with Link Fields

Lookup fields depend on Link fields:

• A Link field must be created first before the corresponding source table can be selected.
• One Link field can be referenced by multiple Lookup fields.
• Deleting a Link field will invalidate the Lookup fields that depend on it.

Suggestions

• Use Original mode for simple references.
• For one-to-many relationships requiring summary statistics, use aggregation modes such as Sum, Count, or Average.
• Add filter conditions when you need to exclude some linked records.