nocodb/packages/noco-docs/docs/100.data-source/010.data-source-overview.md

title	description
Data Sources overview	NocoDB Data-Source sync, access control & re-config

Overview

NocoDB allows you to connect to external data sources and get a unified spreadsheet view of your data. Activities related to external data sources can be managed from Data Sources tab in Base dashboard.

Data Sources tab includes following functionalities

1. Connect/manage external data source
2. UI Access Control
3. Relations
4. Audit logs

:::info Currently only one external data source can be added per project. :::

Accessing Data Sources

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab

Sync Metadata

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab
3. Click on Sync Metadata button listed under Actions column for the data source that you wish to sync metadata for
4. [Optional] Click on Reload button to refresh Sync state.
5. Any changes to the metadata identified will be listed in the Sync State column
6. Click on Sync Now button to sync the metadata changes

After the sync is complete, you can see the updated state in the Sync State column. Sync modal also marks Tables metadata is in Sync in the header.

UI Access Control

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab
3. Click on UI ACL button listed under Actions column for the data source that you wish to manage UI access control for
4. On the UI ACL modal, you can see the list of tables available in the data source as rows & roles available as columns. Toggle checkboxes to enable/disable access to tables for specific roles.
5. Click on Save button to save the changes

Audit logs

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab
3. Click on Audit button listed under Actions column for the data source that you wish to access Audit logs for

Relations

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab
3. Click on Relations button listed under Actions column for the data source that you wish to access ERD (Relations view) for

Junction table names within Relations

• Enable Show M2M Tables within Project Settings menu
• Double-click on Show Columns to see additional checkboxes get enabled.
  • Enabling which you should be able to see junction tables and their table names.

Edit external database configuration parameters

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab
3. Click on Edit icon listed under Actions column for the data source that you wish to access ERD (Relations view) for Go to Data Sources, click Edit icon, you can re-configure database credentials.
   Please make sure database configuration parameters are valid. Any incorrect parameters could lead to schema loss!

Unlink data source

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab
3. Click on Delete icon listed under Actions column for the data source that you wish to Unlink

Data source visibility

1. Access Base context menu by clicking on the Base name in the left sidebar
2. Click on Data Sources tab
3. Toggle radio button listed under Visibility column for the data source that you wish to hide/un-hide