External Systems

External Systems are used for having an incremental changelog for configured tables and fields. This is useful in integrations through Web Services or the Integration Queue

The external systems feature is used when Dynamics 365 Business Central is integrated with other systems. The main purpose of the module is to keep other systems synchronized with Dynamics 365 Business Central by creating log entries. These log entries are then retrieved by the external system via Web Services. Once the log entries are fetched the external system performs a read call on the appropriate Web Service to refresh the data in the external system.

External Systems Overview

It is possible to log and retrieve logged records from any table in Dynamics 365 Business Central, but it is not recommended to log tables that are intensively updated with a high number of new or changed records, as it can cause tables to lock and performance deterioration. The Web Services in Spider can be used to read data from specific tables and fields. If there is a need to publish other pages or codeunits within Dynamics 365 Business Central, see information on how to publish web services on Microsoft Docs

Flow External Systems API

External Systems Flow

The flow needs to be repeated frequently, possibly with a scheduler.

  1. External system calls spiderExternalSystemAPI.GetChangedRecords() with an empty fetchId asking if there are changed records.
  2. spiderExternalSystemAPI.GetChangedRecords() checks the Unsynchronized list for changed records.
  3. If spiderExternalSystemAPI.GetChangedRecords() does not find changes fetchId will be returned empty and the External System knows there are no changed records and the call will end.
  4. If spiderExternalSystemAPI.GetChangedRecords() does find changes fetchId will be given a GUID to pack the changes and returns the fetchId and key of changed records.
  5. External system calls relevant Web service to get the changes
  6. External system calls spiderExternalSystemAPI.GetChangedRecords() with a fetchId and asks if there are changed records. Step 3 to 6 will repeat until there are no changed records.

To create a new External System manually

  1. Choose the search icon, enter External Systems, and then choose the related link.
  2. On the External Systems list, choose the New action.
  3. A new External Systems card opens. Proceed to fill the fields on the External systems card as necessary.
  4. Navigate to Table Setup to add tables and fields, with or without filters.

To create a new External System with a guide

  1. Choose the search icon, enter External Systems Setup Guide, and then choose the related link.