Link Field

Link fields are used to establish relationships between two tables, supporting one-to-one, one-to-many, and many-to-many relationship modes. Through link fields, you can achieve cross-table data linkage, referencing, and summary analysis.

When to Use

• Projects table linked to Tasks table: one project contains multiple tasks
• Customers table linked to Orders table: one customer has multiple orders
• Employees table linked to Departments table: multiple employees belong to one department
• Products table linked to Suppliers table: one product can be supplied by multiple suppliers

Creating a Link Field

1. Click Add Field in a table.
2. Select the Link field type.
3. Configure link parameters:
   • Target Table: Select another table to link to.
   • Relationship Type: Choose one-to-one, one-to-many, or many-to-many.
   • Display Field: Select which field value from the target table to display in the current table.
   • Bidirectional Link: Whether to automatically create a reverse link field in the target table.
4. Click Save.

Relationship Types

Relationship Type	Description	Example
One-to-one	One record in the current table links to only one record in the target table	Employee ↔ Desk
One-to-many	One record in the current table can link to multiple records in the target table	Project → Multiple Tasks
Many-to-many	Records in both tables can link to multiple records in the other table	Product ↔ Multiple Suppliers

Link Record Operations

Adding a Link

• Click the + or search icon in the cell.
• Search and select target records in the record selector popup.
• Supports selecting multiple records at once (in one-to-many/many-to-many modes).

Removing a Link

• Hover over the linked record tag.
• Click the × on the right side of the tag to remove the link.
• Removing a link does not delete the target table record; it only disconnects the relationship.

Viewing Linked Record Details

• Click a linked record tag to open the target record detail drawer.
• The detail drawer shows all fields of the linked record, read-only by default.

Bidirectional Link

When bidirectional link is enabled, SmartTable automatically creates a reverse link field in the target table pointing back to the current table. This means:

• Table A can see linked records from Table B.
• Table B can also see linked records from Table A.
• Adding or removing a link on either side will sync to the other side.

Suggestion

When designing table structures, enable bidirectional links for relationships that need to be viewed from both sides, avoiding the need to manually maintain two link fields later.

Using with Lookup Fields

Link fields are often used together with Lookup fields:

1. First, use a Link field to establish the table relationship.
2. Then, use a Lookup field to extract target field values from linked records.
3. You can also aggregate the lookup results (such as sum, count, etc.).

Notes

• Link fields only store record IDs, not duplicate target data.
• After a target table record is deleted, the corresponding link in the link field disappears automatically.
• Changing the relationship type may affect existing data; please operate with caution.