1.You can back up a content database by using the SharePoint Central Administration website, Microsoft PowerShell, or SQL Server tools.
Reference: https://learn.microsoft.com/en-us/sharepoint/administration/back-up-a-content-database
2.If you migrate SharePoint 2010 to Microsoft 365, you will see your contents in the SharePoint Online. You also could use the Azure portal query editor to query Azure SQL Database.
Reference: https://learn.microsoft.com/en-us/azure/azure-sql/database/connect-query-portal?view=azuresql
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