What are functions or keywords in SQL Server database which will not work in Azure SQL database

When migrating from SQL Server to Azure SQL Database, there are certain features, functions, or keywords that might not be available or might behave differently due to the nature of Azure SQL Database being a Platform as a Service (PaaS) offering. Some of the features that might not work or might have limitations include:

1. SQL Server Agent: Azure SQL Database does not support SQL Server Agent. You need to use Azure Automation, Azure Functions, or other Azure services for similar functionalities.

2. Cross-Database Queries: Azure SQL Database does not support cross-database queries. You can't reference objects in other databases directly. However, you can achieve similar functionality using Elastic Query.

3. Linked Servers: Azure SQL Database does not support linked servers. You have to use other mechanisms like Azure SQL Managed Instance or Azure Data Factory for similar functionalities.

4. SQLCLR: Azure SQL Database does not support SQL Common Language Runtime (SQLCLR). You can't use .NET assemblies or CLR stored procedures directly.

5. Filestream/Filetable: Azure SQL Database does not support FILESTREAM or Filetable. You can use Azure Blob Storage for similar functionalities.

6. Service Broker: Azure SQL Database does not support Service Broker. You need to use other Azure services for message queuing and asynchronous processing.

7. Extended Events: Azure SQL Database does not support extended events. You need to use Azure Monitor for monitoring and diagnostics.

8. SQL Server Integration Services (SSIS): While Azure SQL Database does not directly support SSIS, you can use Azure Data Factory for similar ETL (Extract, Transform, Load) capabilities.

9. SQL Server Analysis Services (SSAS): Azure SQL Database does not support SSAS. You can use Azure Analysis Services for similar OLAP (Online Analytical Processing) capabilities.

10. SQL Server Reporting Services (SSRS): Azure SQL Database does not support SSRS. You can use Power BI or Azure SQL Managed Instance for similar reporting capabilities.

11. Database Mail: Azure SQL Database does not support Database Mail. You need to use other mechanisms for sending emails, such as Azure Functions or external services.

12. SQL Server Profiler: Azure SQL Database does not support SQL Server Profiler. You need to use Extended Events or other Azure monitoring tools for performance monitoring.

13. Certain Database Engine Features: Some features of the SQL Server database engine might not be available or behave differently in Azure SQL Database due to the differences in architecture and service model.

Always refer to the official Azure SQL Database documentation for the most up-to-date information on features and functionalities supported in Azure SQL Database. Additionally, before migration, it's crucial to thoroughly test your application to ensure compatibility with Azure SQL Database.