> ## 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 with Auto Join Condition > ## 1️⃣ Overview **Purpose:** Creates a new LINK type column with an automatic join condition between the parent and child tables. Unlike a manual link, this allows defining column-level join conditions that filter how records are linked. This endpoint supports: - Defining join conditions between columns of two tables - Using operators like `EQUALS` for condition matching - Passing a raw SQL-style `whereClause` and `formula` for backend filtering --- ## 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": { "associateTableId": "uuid", "associateWorkspaceId": "uuid", "whereClause": "string" }, "uiMetadata": { "title": "string", "autoJoinConfig": { "joinConditions": [ { "id": "string", "currentTableColumn": "string", "linkedTableColumn": "string", "operator": "EQUALS" } ], "isSwapped": false } }, "formula": "string", "name": "string" } ``` --- ## 7️⃣ Field Descriptions | Field | Type | Required | Description | | --- | --- | --- | --- | | uiDataType | string | ✅ Yes | Must be `LINK` | | colOptions.associateTableId | UUID | ✅ Yes | The child or linked table ID | | colOptions.associateWorkspaceId | UUID | ✅ Yes | The workspace ID of the child (associated) table | | colOptions.whereClause | string | ✅ Yes | Raw SQL-style condition used for backend join filtering | | uiMetadata.title | string | ✅ Yes | Display name shown in the UI | | uiMetadata.autoJoinConfig | object | ✅ Yes | Configuration object defining the auto join conditions | | uiMetadata.autoJoinConfig.joinConditions | array | ✅ Yes | List of join condition objects | | uiMetadata.autoJoinConfig.joinConditions[].id | string | ✅ Yes | Unique identifier for the condition (client-generated) | | uiMetadata.autoJoinConfig.joinConditions[].currentTableColumn | string | ✅ Yes | Column name from the current (source) table to join on | | uiMetadata.autoJoinConfig.joinConditions[].linkedTableColumn | string | ✅ Yes | Column name from the linked (destination) table to join on | | uiMetadata.autoJoinConfig.joinConditions[].operator | string | ✅ Yes | Join operator — currently supports `EQUALS` | | uiMetadata.autoJoinConfig.isSwapped | boolean | ❌ No | Whether the join direction is swapped. Defaults to `false` | | formula | string | ✅ Yes | Raw SQL-style formula matching the whereClause, used for backend processing | | name | string | ✅ Yes | Internal column name — must be unique within the table | ## OpenAPI ````yaml /openapi/openapi.yaml post /noCo/api/v2/workspaces/{workspace_id}/tables/{table_id}/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/{workspace_id}/tables/{table_id}/column: post: tags: - Links & Joins summary: Create Link Column with Auto Join Condition description: >- ## 1️⃣ Overview **Purpose:** Creates a new LINK type column with an automatic join condition between the parent and child tables. Unlike a manual link, this allows defining column-level join conditions that filter how records are linked. This endpoint supports: - Defining join conditions between columns of two tables - Using operators like `EQUALS` for condition matching - Passing a raw SQL-style `whereClause` and `formula` for backend filtering --- ## 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": { "associateTableId": "uuid", "associateWorkspaceId": "uuid", "whereClause": "string" }, "uiMetadata": { "title": "string", "autoJoinConfig": { "joinConditions": [ { "id": "string", "currentTableColumn": "string", "linkedTableColumn": "string", "operator": "EQUALS" } ], "isSwapped": false } }, "formula": "string", "name": "string" } ``` --- ## 7️⃣ Field Descriptions | Field | Type | Required | Description | | --- | --- | --- | --- | | uiDataType | string | ✅ Yes | Must be `LINK` | | colOptions.associateTableId | UUID | ✅ Yes | The child or linked table ID | | colOptions.associateWorkspaceId | UUID | ✅ Yes | The workspace ID of the child (associated) table | | colOptions.whereClause | string | ✅ Yes | Raw SQL-style condition used for backend join filtering | | uiMetadata.title | string | ✅ Yes | Display name shown in the UI | | uiMetadata.autoJoinConfig | object | ✅ Yes | Configuration object defining the auto join conditions | | uiMetadata.autoJoinConfig.joinConditions | array | ✅ Yes | List of join condition objects | | uiMetadata.autoJoinConfig.joinConditions[].id | string | ✅ Yes | Unique identifier for the condition (client-generated) | | uiMetadata.autoJoinConfig.joinConditions[].currentTableColumn | string | ✅ Yes | Column name from the current (source) table to join on | | uiMetadata.autoJoinConfig.joinConditions[].linkedTableColumn | string | ✅ Yes | Column name from the linked (destination) table to join on | | uiMetadata.autoJoinConfig.joinConditions[].operator | string | ✅ Yes | Join operator — currently supports `EQUALS` | | uiMetadata.autoJoinConfig.isSwapped | boolean | ❌ No | Whether the join direction is swapped. Defaults to `false` | | formula | string | ✅ Yes | Raw SQL-style formula matching the whereClause, used for backend processing | | name | string | ✅ Yes | Internal 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: Source (parent) table identifier requestBody: required: true content: application/json: schema: type: object required: - uiDataType - colOptions - uiMetadata - formula - name properties: uiDataType: type: string enum: - LINK colOptions: type: object required: - associateTableId - associateWorkspaceId - whereClause properties: associateTableId: type: string format: uuid description: The child or linked table ID associateWorkspaceId: type: string format: uuid description: The workspace ID of the child (associated) table whereClause: type: string description: Raw SQL-style condition used for backend join filtering uiMetadata: type: object required: - title - autoJoinConfig properties: title: type: string description: Display name shown in the UI autoJoinConfig: type: object properties: joinConditions: type: array items: type: object properties: id: type: string description: >- Unique identifier for the condition (client-generated) currentTableColumn: type: string description: >- Column name from the current (source) table to join on linkedTableColumn: type: string description: >- Column name from the linked (destination) table to join on operator: type: string enum: - EQUALS description: Join operator isSwapped: type: boolean description: >- Whether the join direction is swapped. Defaults to false formula: type: string description: >- Raw SQL-style formula matching the whereClause, used for backend processing name: type: string description: Internal column name — must be unique within the table example: uiDataType: LINK colOptions: associateTableId: 6d85b345-b626-4b87-b664-66237d7333e8 associateWorkspaceId: b3e1a902-1234-4abc-9def-7f8a90bc1234 whereClause: table_1e67d485."course_taken" = table_c8be6d9c."status" uiMetadata: title: product link column autoJoinConfig: joinConditions: - id: condition-1774312716137 currentTableColumn: course_taken linkedTableColumn: status operator: EQUALS isSwapped: false formula: table_1e67d485."course_taken" = table_c8be6d9c."status" name: product_link_column responses: '200': description: Link column with auto join condition 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 formula: type: string description: Raw SQL-style formula used for the join condition backendDataType: type: string description: Underlying database data type assigned to the column workspaceId: type: string format: uuid description: Workspace this column belongs to colOptions: type: object properties: id: type: string format: uuid description: Unique identifier of the colOptions record relationType: type: string description: >- Relation type resolved by the server — 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 whereClause: type: string description: >- Raw SQL-style condition used for backend join filtering 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 autoJoinConfig: type: object properties: joinConditions: type: array items: type: object properties: id: type: string currentTableColumn: type: string linkedTableColumn: type: string operator: type: string isSwapped: type: boolean tableId: type: string format: uuid description: Table ID where this column resides example: id: efdbce09-6581-4811-aa67-14344e7444b7 name: product link column uiDataType: LINK formula: table_1e67d485."course_taken" = table_c8be6d9c."status" backendDataType: VARCHAR(255) workspaceId: 16231f3f-8208-4c51-a460-87d17244344f colOptions: id: e19ab19c-3a38-4d28-9eff-767019524186 relationType: MANY_TO_MANY columnId: efdbce09-6581-4811-aa67-14344e7444b7 associatedColumnId: 9422e52d-9886-431e-946f-8ed5a8838dac tableId: 9c8a448d-7884-4158-bfca-202bc95b0515 associateTableId: 6d85b345-b626-4b87-b664-66237d7333e8 associateWorkspaceId: b3e1a902-1234-4abc-9def-7f8a90bc1234 childColumnId: 75272cd2-63c4-4d4c-b2eb-20a864834a2a parentColumnId: f830fd3f-8624-4ae5-959f-36f1756d828a whereClause: table_1e67d485."course_taken" = table_c8be6d9c."status" isItSource: true uiMetadata: title: product_link_column autoJoinConfig: joinConditions: - id: condition-1774312716137 currentTableColumn: course_taken linkedTableColumn: status operator: EQUALS isSwapped: false tableId: 9c8a448d-7884-4158-bfca-202bc95b0515 security: - bearerAuth: [] components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: | This API uses OAuth 2.0 with the authorization code grant flow. ````