> ## Documentation Index > Fetch the complete documentation index at: https://api-docs.datagol.ai/llms.txt > Use this file to discover all available pages before exploring further. # Add Lookup Column > ## 1️⃣ Overview **Purpose:** Adds one or more LOOKUP type columns to a specified table. A lookup column pulls field values from a linked (associated) table via an existing LINK column. --- ## 2️⃣ Endpoint ``` POST /noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/columns ``` --- ## 3️⃣ Path Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | workspaceId | UUID | ✅ Yes | Workspace identifier | | tableId | UUID | ✅ Yes | Table identifier where the lookup column will be created | --- ## 4️⃣ Authentication Requires **Bearer JWT Token** ``` Authorization: Bearer ``` --- ## 5️⃣ Request Headers | Header | Required | | --- | --- | | Authorization | ✅ Yes | | Content-Type: application/json | ✅ Yes | --- ## 6️⃣ Request Body Schema ```json { "columns": [ { "description": "string", "uiMetadata": { "title": "string" }, "uiDataType": "LOOKUP", "colOptions": { "linkColumnId": "uuid", "lookupColumnId": "uuid" }, "name": "string" } ] } ``` --- ## 7️⃣ Field Descriptions | Field | Type | Required | Description | | --- | --- | --- | --- | | columns | array | ✅ Yes | Array of lookup column definitions to create | | columns[].description | string | ❌ No | Optional description of the column | | columns[].uiMetadata.title | string | ✅ Yes | Display name shown in the UI | | columns[].uiDataType | string | ✅ Yes | Must be `LOOKUP` | | columns[].colOptions.linkColumnId | UUID | ✅ Yes | ID of the existing LINK column connecting to the source table | | columns[].colOptions.lookupColumnId | UUID | ✅ Yes | ID of the column in the linked table whose values should be looked up | | columns[].name | string | ✅ Yes | Internal column name — must be unique within the table | --- ## 8️⃣ Example Request ```bash curl -X POST https://be.datagol.ai/noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/columns \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "columns": [ { "description": "", "uiMetadata": { "title": "Name (from People)" }, "uiDataType": "LOOKUP", "colOptions": { "linkColumnId": "21224153-2f85-4b24-a306-4cfbc7e73f70", "lookupColumnId": "9b5e408d-69bb-42ca-8fa4-ba00f7994356" }, "name": "name_1774285509977" } ] }' ``` --- ## 9️⃣ Behavior Summary ``` Creates one or more LOOKUP columns in the target table. Supports: • Batch creation of multiple lookup columns in one request • linkColumnId — references the existing LINK column in the current table • lookupColumnId — references the column from the linked table to display • Column name must be unique within the table ``` ## OpenAPI ````yaml /openapi/openapi.yaml post /noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/columns openapi: 3.0.0 info: title: DataGOL APIs version: 1.0.0 description: '' servers: - url: https://be.datagol.ai - url: https://be.datagol.ai - url: https://kg.datagol.ai - url: https://ai.datagol.ai security: [] tags: - name: Links & Joins description: > ## 🔗 Links & Joins LINK and LOOKUP are special workbook column types that enable relational data modeling across tables. | Column Type | Purpose | |---|---| | `LINK` | Defines a relationship between two tables | | `LOOKUP` | Projects columns from an associated table via a link | Both are configured through `ColumnDTO.colOptions`. A table can have multiple link columns, and each link can have multiple lookup columns. --- ## 📐 UI Data Types - **LINK** — Special column used to represent inter-table relations - **LOOKUP** — Special column used to project associated table fields via a link --- ## 🔗 LINK Semantics A LINK column stores metadata for: - `tableId` — Current table - `associatedTableId` — Associated (linked) table - `relationType` — Type of relationship - `linkColumnId` — Link column identifier **Supported relation patterns:** | Pattern | Description | |---|---| | `ONE_TO_ONE` | Each record in the source maps to one record in the destination | | `ONE_TO_MANY` | One source record maps to many destination records | | `MANY_TO_MANY` | Many source records map to many destination records | --- ## 🔍 LOOKUP Semantics - A LOOKUP column is tightly coupled with a specific LINK column - References a link using `linkColumnId` - Represents a selected column from the associated table - Multiple lookup columns can be defined for the same link --- ## 🗂️ Metadata in `ColumnDTO.colOptions` Use `colOptions` to persist link/lookup metadata. | Field | Description | |---|---| | `columnId` | Current column ID | | `tableId` | Current table ID | | `associatedTableId` | Associated table ID | | `linkColumnId` | Link column ID — used by LOOKUP; references the LINK column's `columnId` | | `relationType` | Relation semantics for LINK | --- ## 🔄 Manual Linking Record Flow To create manual record-level links: 1. Fetch associated table schema/data 2. User selects associated record(s) to link 3. Send linking payload with: - `sourceRecordId` — PK of the current table row - `destinationRecordId` — PK of the associated table row - `linkColumnId` — LINK column identifier 4. Backend resolves link metadata from `linkColumnId` (relation type, associated table, direction/constraints) 5. Backend applies relation rules and stores the link relation --- ## 📋 Record Linking Contract | Field | Description | |---|---| | `sourceRecordId` | PK of the current table row | | `destinationRecordId` | PK of the associated table row | | `linkColumnId` | LINK column identifier | | `tableId` | Current table ID | > Backend derives all remaining relation metadata from the link configuration. --- ## ⚠️ Important Notes > - LINK and LOOKUP are **column-level constructs** first; record linking is a data-level operation built on top > - LOOKUP behavior depends on LINK existence and metadata integrity > - With multiple links to the same associated table, each LOOKUP must bind to the correct `linkColumnId` > - Always treat the associated row ID as the associated table PK for linking UI selection paths: /noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/columns: post: tags: - Links & Joins summary: Add Lookup Column description: >- ## 1️⃣ Overview **Purpose:** Adds one or more LOOKUP type columns to a specified table. A lookup column pulls field values from a linked (associated) table via an existing LINK column. --- ## 2️⃣ Endpoint ``` POST /noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/columns ``` --- ## 3️⃣ Path Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | workspaceId | UUID | ✅ Yes | Workspace identifier | | tableId | UUID | ✅ Yes | Table identifier where the lookup column will be created | --- ## 4️⃣ Authentication Requires **Bearer JWT Token** ``` Authorization: Bearer ``` --- ## 5️⃣ Request Headers | Header | Required | | --- | --- | | Authorization | ✅ Yes | | Content-Type: application/json | ✅ Yes | --- ## 6️⃣ Request Body Schema ```json { "columns": [ { "description": "string", "uiMetadata": { "title": "string" }, "uiDataType": "LOOKUP", "colOptions": { "linkColumnId": "uuid", "lookupColumnId": "uuid" }, "name": "string" } ] } ``` --- ## 7️⃣ Field Descriptions | Field | Type | Required | Description | | --- | --- | --- | --- | | columns | array | ✅ Yes | Array of lookup column definitions to create | | columns[].description | string | ❌ No | Optional description of the column | | columns[].uiMetadata.title | string | ✅ Yes | Display name shown in the UI | | columns[].uiDataType | string | ✅ Yes | Must be `LOOKUP` | | columns[].colOptions.linkColumnId | UUID | ✅ Yes | ID of the existing LINK column connecting to the source table | | columns[].colOptions.lookupColumnId | UUID | ✅ Yes | ID of the column in the linked table whose values should be looked up | | columns[].name | string | ✅ Yes | Internal column name — must be unique within the table | --- ## 8️⃣ Example Request ```bash curl -X POST https://be.datagol.ai/noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/columns \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "columns": [ { "description": "", "uiMetadata": { "title": "Name (from People)" }, "uiDataType": "LOOKUP", "colOptions": { "linkColumnId": "21224153-2f85-4b24-a306-4cfbc7e73f70", "lookupColumnId": "9b5e408d-69bb-42ca-8fa4-ba00f7994356" }, "name": "name_1774285509977" } ] }' ``` --- ## 9️⃣ Behavior Summary ``` Creates one or more LOOKUP columns in the target table. Supports: • Batch creation of multiple lookup columns in one request • linkColumnId — references the existing LINK column in the current table • lookupColumnId — references the column from the linked table to display • Column name must be unique within the table ``` parameters: - name: workspaceId in: path required: true schema: type: string format: uuid description: Workspace identifier - name: tableId in: path required: true schema: type: string format: uuid description: Table identifier where the lookup column will be created requestBody: required: true content: application/json: schema: type: object required: - columns properties: columns: type: array items: type: object required: - uiDataType - uiMetadata - colOptions - name properties: description: type: string uiMetadata: type: object properties: title: type: string uiDataType: type: string enum: - LOOKUP colOptions: type: object required: - linkColumnId - lookupColumnId properties: linkColumnId: type: string format: uuid description: >- ID of the existing LINK column in the current table lookupColumnId: type: string format: uuid description: ID of the column in the linked table to look up name: type: string example: columns: - description: '' uiMetadata: title: lookup column uiDataType: LOOKUP colOptions: linkColumnId: 21224153-2f85-4b24-a306-4cfbc7e73f70 lookupColumnId: 9b5e408d-69bb-42ca-8fa4-ba00f7994356 name: lookup_column responses: '200': description: Lookup column(s) created successfully security: - bearerAuth: [] components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: | This API uses OAuth 2.0 with the authorization code grant flow. ````