CODEWITHSUNDEEP
vb.netazure
Kyle Moffat
Kyle Moffat

Reputation: 173

Storing files in Azure SQLdatabase

I have a vb.net based application which references an Azure SQL Database, I have set up a storage account to which I would like to store files to from the application. I am not sure how to create that link between the DB and the Storage account?

Going through the "SQL Server Data Files in Windows Azure Storage service" Tutorial I cannot create a URI for the sotrage blob. Using Azure Storage Explorer I select my container go into security and generate a signature which all works fine. When I test the URI with the "Test in Browser" button I get this error:

 <Error>
 <Code>AuthenticationFailed</Code>
 <Message>
 Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature. RequestId:22ab2830-0001-001d-67a0-5460bb000000 Time:2014-10-17T14:06:11.9864269Z
 </Message>
 <AuthenticationErrorDetail>
 Signature did not match. String to sign used was r 2014-10-17T06:00:00Z 2014-10-25T06:00:00Z /macrocitrus/$root 2014-02-14
 </AuthenticationErrorDetail>
 </Error>

to what this means I have no idea. I am a completely new user with Windows Azure so I am not even sure that I am on the right track?

Is there any documentation that actually explains the steps or what one would require to allow storage access from an SQL DB to an Azure Storage account?

Upvotes: 2

Views: 3308

Answers (1)

Gaurav Mantri
Gaurav Mantri

Reputation: 136346

I would not recommend saving the binary content in SQL Database. Instead I would recommend that you save them in blob storage. Here are my reasons for doing so:

  • Blob storage is designed for that purpose.
  • Storing data in blob storage is much-much cheaper than storing the data in SQL Database.
  • By storing binary data with other data, you're unnecessarily making your data access layer bulkier as all the data will be streamed through your database.

General approach in these kinds of scenarios is to keep binary data in blob storage as blobs (think of blobs as files in the cloud). Since each blob gets a unique URL, you can just store the URL in your SQL Database table. So if we go with this approach, what you will be doing is first uploading the blob in blob storage, get its URL and then update the database.

If you search for uploading files in blob storage, I am sure you will find a lot of examples with source code (so I will not bother providing it here :); I hope its all right).

Now coming to the error you're getting. Basically the link you created using Azure Storage Explorer is known as Shared Access Signature (SAS) URL which basically grants a time-limited/permission bound access to your storage account. Now Azure Storage Explorer gave you a SAS URL for the container. There are two ways you can use that URL (assuming you granted Read & List permissions when creating the SAS URL:

  • To list blobs in that container, just append restype=container&comp=list to your URL and then paste it in the browser and you will see an XML listing of all blobs.
  • To download a blob, you would need to insert the name of the blob in the URL. So if your URL is like https://[youraccount].blob.core.windows.net/[yourcontainer]?[somestuffhere] and your blob name is myawesomepicture.png, your SAS URL for viewing the file in the browser would be https://[youraccount].blob.core.windows.net/[yourcontainer]/myawesomepicture.png?[somestuffhere]

I wrote a blog post on using Shared Access Signatures which you may find useful: http://gauravmantri.com/2013/02/13/revisiting-windows-azure-shared-access-signature/.

Upvotes: 6

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