We have Office 365 E3 account. Hence, I can not use any database on the cloud.But I have a business requirement to store the information in relational manner. So, at any cost I need to store my data in a relational database. What is the best way to create a database over cloud? Can I use MS-Access? If yes, how can I connect to Access database in my sandboxed solution. I am using SharePoint 2013 online as part of Office 365.
what you mean by storing the data in relational manner? you want use the sharepoint as front end just display the data then you can use BCS or you can also use Access Web App.