> ## 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. # Create Link Column (Manual-Link) > ## 1️⃣ Overview **Purpose:** Creates a new LINK type column in a table, establishing a bidirectional relationship between a parent table and a child/associated table. This endpoint supports: - Creating HAS_MANY, ONE_TO_ONE, and MANY_TO_MANY relation types - Automatically creating a reciprocal link column in the associated table > ⚠️ **Note:** Links are bidirectional. When a link is created from the parent with relation type `HAS_MANY`, a corresponding column with relation type `BELONGS_TO` is automatically created in the child table. --- ## 2️⃣ Endpoint ``` POST /noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/column ``` --- ## 3️⃣ Path Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | workspaceId | UUID | ✅ Yes | Workspace identifier | | tableId | UUID | ✅ Yes | Source (parent) table identifier | --- ## 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 { "uiDataType": "LINK", "colOptions": { "relationType": "HAS_MANY", "associateTableId": "uuid", "associateWorkspaceId": "uuid" }, "uiMetadata": { "title": "string" }, "settings": {}, "name": "string" } ``` --- ## 7️⃣ Field Descriptions | Field | Type | Required | Description | | --- | --- | --- | --- | | uiDataType | string | ✅ Yes | Must be `LINK` | | colOptions.relationType | string | ✅ Yes | Relation type: `HAS_MANY`, `ONE_TO_ONE`, or `MANY_TO_MANY` | | colOptions.associateTableId | UUID | ✅ Yes | The child or linked table ID | | colOptions.associateWorkspaceId | UUID | ✅ Yes | The workspace ID of the child (associated) table | | uiMetadata.title | string | ✅ Yes | Display name shown in the UI | | 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}/column \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "uiDataType": "LINK", "colOptions": { "relationType": "HAS_MANY", "associateTableId": "6a175502-6458-4314-b4c5-3c2f29626dea", "associateWorkspaceId": "b3e1a902-1234-4abc-9def-7f8a90bc1234" }, "uiMetadata": { "title": "people" }, "name": "people" }' ``` --- ## 9️⃣ Behavior Summary ``` Creates a LINK column in the source table. Supports: • HAS_MANY, ONE_TO_ONE, and MANY_TO_MANY relation types • Bidirectional — a BELONGS_TO column is auto-created in the child table • Column name must be unique within the table • Returns the full column object including colOptions with resolved IDs ``` ## OpenAPI ````yaml /openapi/openapi.yaml post /noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/column 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}/column: post: tags: - Links & Joins summary: Create Link Column (Manual-Link) description: >- ## 1️⃣ Overview **Purpose:** Creates a new LINK type column in a table, establishing a bidirectional relationship between a parent table and a child/associated table. This endpoint supports: - Creating HAS_MANY, ONE_TO_ONE, and MANY_TO_MANY relation types - Automatically creating a reciprocal link column in the associated table > ⚠️ **Note:** Links are bidirectional. When a link is created from the parent with relation type `HAS_MANY`, a corresponding column with relation type `BELONGS_TO` is automatically created in the child table. --- ## 2️⃣ Endpoint ``` POST /noCo/api/v2/workspaces/{workspaceId}/tables/{tableId}/column ``` --- ## 3️⃣ Path Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | workspaceId | UUID | ✅ Yes | Workspace identifier | | tableId | UUID | ✅ Yes | Source (parent) table identifier | --- ## 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 { "uiDataType": "LINK", "colOptions": { "relationType": "HAS_MANY", "associateTableId": "uuid", "associateWorkspaceId": "uuid" }, "uiMetadata": { "title": "string" }, "settings": {}, "name": "string" } ``` --- ## 7️⃣ Field Descriptions | Field | Type | Required | Description | | --- | --- | --- | --- | | uiDataType | string | ✅ Yes | Must be `LINK` | | colOptions.relationType | string | ✅ Yes | Relation type: `HAS_MANY`, `ONE_TO_ONE`, or `MANY_TO_MANY` | | colOptions.associateTableId | UUID | ✅ Yes | The child or linked table ID | | colOptions.associateWorkspaceId | UUID | ✅ Yes | The workspace ID of the child (associated) table | | uiMetadata.title | string | ✅ Yes | Display name shown in the UI | | 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}/column \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "uiDataType": "LINK", "colOptions": { "relationType": "HAS_MANY", "associateTableId": "6a175502-6458-4314-b4c5-3c2f29626dea", "associateWorkspaceId": "b3e1a902-1234-4abc-9def-7f8a90bc1234" }, "uiMetadata": { "title": "people" }, "name": "people" }' ``` --- ## 9️⃣ Behavior Summary ``` Creates a LINK column in the source table. Supports: • HAS_MANY, ONE_TO_ONE, and MANY_TO_MANY relation types • Bidirectional — a BELONGS_TO column is auto-created in the child table • Column name must be unique within the table • Returns the full column object including colOptions with resolved IDs ``` 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: Source (parent) table identifier requestBody: required: true content: application/json: schema: type: object required: - uiDataType - colOptions - uiMetadata - name properties: uiDataType: type: string enum: - LINK colOptions: type: object required: - relationType - associateTableId - associateWorkspaceId properties: relationType: type: string enum: - HAS_MANY - ONE_TO_ONE - MANY_TO_MANY associateTableId: type: string format: uuid associateWorkspaceId: type: string format: uuid uiMetadata: type: object properties: title: type: string name: type: string example: uiDataType: LINK colOptions: relationType: HAS_MANY associateTableId: 6a175502-6458-4314-b4c5-3c2f29626dea associateWorkspaceId: b3e1a902-1234-4abc-9def-7f8a90bc1234 uiMetadata: title: people name: people responses: '200': description: Link column created successfully content: application/json: schema: type: object properties: id: type: string format: uuid description: Unique identifier of the created link column name: type: string description: Internal column name, unique within the table uiDataType: type: string description: Always returns `LINK` for link columns colOptions: type: object properties: id: type: string format: uuid description: Unique identifier of the colOptions record relationType: type: string description: Relation type — HAS_MANY, ONE_TO_ONE, or MANY_TO_MANY columnId: type: string format: uuid description: ID of the link column in the source (parent) table associatedColumnId: type: string format: uuid description: >- ID of the auto-created reciprocal column in the child table tableId: type: string format: uuid description: Source table ID where the link column was created associateTableId: type: string format: uuid description: Destination (child) table ID associateWorkspaceId: type: string format: uuid description: Workspace ID of the destination (child) table childColumnId: type: string format: uuid description: >- ID of the primary key column in the child (destination) table, used to establish the foreign key relationship. parentColumnId: type: string format: uuid description: >- ID of the primary key column in the parent (source) table, used to establish the foreign key relationship. isItSource: type: boolean description: >- True if this column is the source side of the relationship uiMetadata: type: object properties: title: type: string description: Display name shown in the UI example: id: 21224153-2f85-4b24-a306-4cfbc7e73f70 name: people uiDataType: LINK colOptions: id: 28dde853-fc6e-4983-8121-b013f2b85e80 relationType: HAS_MANY columnId: 21224153-2f85-4b24-a306-4cfbc7e73f70 associatedColumnId: 518e2dfc-f8c9-459e-ac7e-99f3daa6d773 tableId: 2815ed2f-5acc-400d-94a9-ae5596da2c37 associateTableId: 6a175502-6458-4314-b4c5-3c2f29626dea associateWorkspaceId: b3e1a902-1234-4abc-9def-7f8a90bc1234 childColumnId: d1d1e3f0-8a3f-48e5-b93e-9e3f3d1ef4ff parentColumnId: 9f642d9c-54ae-4801-95fe-e83e452b5b4b isItSource: true uiMetadata: title: people security: - bearerAuth: [] components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: | This API uses OAuth 2.0 with the authorization code grant flow. ````