参考我的回答在其他帖子中，这里有更多细节。

Hi,

I am working in a project wherein existing application is running in SharePoint 2010 and DB server is SQL Server 2008 R2. Client has multiple tables, views, stored procedures, functions and jobs in an external database in this server apart from Content DB of SharePoint.

There is an external integration with Oracle ERP i.e. HRMS in SQL Server external DB. In existing application, HRMS team is giving a view to SQL Server using a link server and then HRMS data is accessed using code. (Along with Active Directory, HRMS is also used to get user details in SharePoint 2010 i.e user properties)

Requirement - I need to implement this scenario in SharePoint Online (Office 365). Client is planning to move existing SP 2010 application to SPO. Please suggest how can I access this HRMS data in SharePoint Online application via code or by any other means.

Do I need to use Azure for this purpose. Please suggest.

Any help would be highly appreciable !

Refer to my answer in other thread, some more details here.