Reports for web and MSSQL or Oracle

What is the best strategy for implementing we reports using an MSSQL database or Oracle database?

Depends where your app runs.
You can use:

With designer
Crystal reports (sap) only for Windows Valutation 10+
Valentina report (paradigma software) multiplatform valutation 7

Without designer:
Turbo report, free or with donation
Mbs
There are other class …