I am using xamarin Azure SDK to download and manage the local database for my Xamarin . Forms App.
We are facing downloading time issues because we have a lot of data,
so I am thinking of taking backup once of the SQLite File from one device and use it to restore on different devices as restoring the same SQLite File.
Planned to use Azure Blob storage to store backup of SQLite files and for different device planning to download that blob of SQLite file and thinking of restore it on different devices.
Any Help will be appreciated.
Thanks :)
An approach I have used in the past is to create a controller method on the azure end which the client app can call that generates a pre-filled sqlite database or 'snapshot' on the server (making sure you include all the extra azure tables and columns) and then return a download url for the file to the client. We also zip-up the snapshot database to reduce the download times. You could store this 'snapshot' in azure blob if you desired.
Please refer given link. SQLite is not supporting only relationship like Foreign Key.
Memory Stream as DB
you can upload back up file on Blob with respective user details. and when there is any call with same user details you can download it from blob.
Those are the links that provide you with the code / knowledge required to use Azure Blob Storage on Xamarin:
https://learn.microsoft.com/en-us/azure/storage/blobs/storage-xamarin-blob-storage
https://learn.microsoft.com/en-us/azure/storage/blobs/storage-dotnet-how-to-use-blobs
As this question is very general I can provide you only with those general links. There are many details on how to implement that in your case, if you face some specific problem I recommend to ask another question with the exact description of that specific problem.
EDIT: According to your comment you have some problems in replacing the local file. The only thing is that you must replace it before you initialize SQLite, otherwise it is a simple file operation.
Related
We are using Logic App to move data from a Sharepoint folder to an Azure Blob Storage.
We were using the Sharepoint trigger "When a file is created or modified in a folder". Unfortunately, this trigger has been deprecated and does not work anymore (i.e., when a file is indeed created or modified, no further action is done after running the trigger).
No file is moved around anymore. The trigger does not execute the Logic App even though a file is created or modified in the Sharepoint origin folder. I have been through the various other Sharepoint triggers but they do not seem to fit our use case. We cannot create a Logic App for each file. We are not using Sharepoint lists but classic folders. We could use several triggers pointing directly at each existin file, but as we have many files to move in the same folder, we would have to create many Logic Apps and that is not how we want to do it. Moreover, some new files may be created in the future.
What could we do to keep the same architecture of moving data around from Sharepoint to Blob Storage through the non-deprecated Logic App triggers?
Thank you in advance,
Alexis
You can use When a file is created or modified (properties only) and get the properties of the file that is getting created or updated. Then you can use Get file content using the properties from the previous step. Finally, you can create a blob using the previous steps. Below is the flow of my logic app.
RESULTS:
I am trying to understand how soft delete and versioning work within azure blog storage.
It seems that if you have both soft delete and versioning turned on... you can’t just ‘undelete ’ deleted files, as versioning actually saves a new version as a deleted file.
So instead you have to promote the last version of each deleted file.
But what if you have a structure of nested folders and thousands of blobs... you can’t just promote the top version of the top level folder... you need to use Powershell to list files with no current version, and promote them? How would you do this?
This seems awfully complicated, when without versioning - a simple ‘undelete’ command is available from the GUI.
Am I missing something? What is the easiest way to ‘undelete’ a nested folder structure of thousand of blobs in folders, when versioning is turned on?
Thanks
As Rob Minson pointed out, the approach involves copying a blob version to the same container. For PowerShell, use the Copy-AzStorageBlob cmdlet; for Azure CLI, use the az storage blob copy start command. You can pass an account key or SAS token, or use Azure AD.
We've updated the documentation to shed some light on an approach to restoring blobs when soft-delete and/or versioning is enabled. Code samples are available for both PowerShell and Azure CLI.
Simply put, no.
The first point that needs to be emphasized is that blobs in blob storage are not nested as you might think. It seems that blob storage is the same as the local file system: some nested folders, and many files inside. But in fact these are fake, the storage structure of blob storage is flat. Blob storage is not about putting a small box in a box and then putting items in the small box. In fact, all blobs are items of blob storage, and there is no such thing as a "small box".
Then, the second point, for blob storage, the soft-delete operation only supports two objects, one is a blob and the other is a container.
Check out this document:
https://learn.microsoft.com/en-us/azure/storage/blobs/soft-delete-container-overview?tabs=azure-cli#how-container-soft-delete-works
However, you can only use container soft delete to restore blobs if
the container itself was deleted. To a restore a deleted blob when its
parent container has not been deleted, you must use blob soft delete
or blob versioning.
So unfortunately, there is no so-called easy way. You need to operate on each blob, the nested structure does not actually exist.
If you are interested, you can read this blog:
https://medium.com/#loopjockey/structuring-azure-blobs-for-functions-8305ba427356
I completely agree that this seems really un-documented at the moment. I've raised a github issue against this docs page to see if they can get the situation improved.
The best path through that I've found is something like the following:
Using Azure Storage Explorer, open up the container with the soft-deleted, versioned blobs, then change the drop down to "All blobs and blobs without current version". Now you can select a blob and hit 'Promote Version'. The deleted blob will be restored and in the Activities pane you can expand the operation and hit 'Copy AzCopy Command to Clipboard'.
The result will show you something like the following:
./azcopy.exe copy
"https://accountname.blob.core.windows.net/containername/blobname?<sastoken>&versionid=2021-04-22T11%3A35%3A36.9385599Z"
"https://accountname.blob.core.windows.net/containername/blobname?<sastoken>"
--overwrite=true
--recursive
--trusted-microsoft-suffixes=;
Now, based on this you can see you have a building block for automating the process you're talking about. Your problem at this point is finding this thing:
versionid=2021-04-22T11%3A35%3A36.9385599Z
Unfortunately that's a timestamp to nanosecond precision which you're not going to be able to infer. There's no functionality I can find in powershell, in the REST APIs or in AzCopy to get this data, the only way I have found is this sample for the .Net SDK.
All this probably means you can either:
Implement your own C# console app using the Azure.Storage.Blobs library to list the versions for each blob, then perform the relevant copy command now you know the magic version string
Wait for the REST API or Powershell library to get the ability to list versions
I have not been able to find a solution to this so will ask the experts.
A co-worker has a .txt file on his laptop that we want to load into Azure SQL DB using SSMS and Bulk Insert. We can open the local file easily enough but we don't know how to reference this file in FROM clause.
Assuming a file named myData.txt is saved to
c:\Users\Someone
how do we tell Azure SQL DB where that file is?
You don't. :) You have to upload a file to an Azure Blob Store and then, from there, you can use BULK INSERT or OPENROWSET to open the file.
https://learn.microsoft.com/en-us/sql/t-sql/statements/bulk-insert-transact-sql?view=sql-server-2017
I've written an article that describes the steps to open a JSON file here:
https://medium.com/#mauridb/work-with-json-files-with-azure-sql-8946f066ddd4
I fixed this problem by uploading the file to a local database and then use a linked server to my Azure db to insert or update the record. Much easier than creating a Blob Storage. However, if the file is very big or you have a lot of files to upload you might not want to use my method as linked servers is not the quickest connection.
I am aware that Azure blob storage does not use an actual folder structure but could not think of a better way to describe this.
The issue we're seeing is when opening Server Explorer (in Visual Studio) to browse through our blob storage container. We separate client resources and data by folder so in this case we have a blob titled productdata/Client_5/testimage.jpg.
The problem is that this Client_5 folder appears twice when inspecting our blob storage. So far I've double checked there are no weird special characters in either folder and double checked case sensitivity. The two paths are EXACTLY the same except its actual contents. Our application has no problems with this because the path is still exactly the same to the resources it's attempting to get. (For example, since the folders are named exactly the same, https://myazureaccount.blob.core.windows.net/productdata/Client_5/image.jpg still takes us to exactly where we need to be.) It's just a pain when we use Server Explorer to view our blobs on Azure because we have two folder locations to check. This could very well be a bug in Server Explorer for Visual Studio as well.
If anyone else has ever come across this, any info is appreciated. I couldn't find anything on the topic when searching online but figure I would post the question here for reference. Also, I'll be contacting Azure support soon to see if they can shed some light on any of this and will post what info I get from them here later.
It's true that blob storage doesn't have the concept of folder but the API built on the top of it does. I've seen exactly the same or similar problems in other tools as well: Microsoft Azure Storage Explorer and even Azure Portal. I tried to go deeper and when I executed:
CloudBlobContainer.ListBlobs(null, useFlatBlobListing: false)
it also returned duplicated directories. To be precise it returned the list with several instances of CloudBlobDirectory that had the same Prefix. Sounds like a bug. Now, if a tool uses this approach to get a list of directories it will fail. If the tool uses flat listing and builds the structure of folders in its logic it should be ok.
Hard to say what is the reason of such behaviour. In my case files in blob storage were copied by Azure Data Factory activity with concurrency option but I'm not sure if it's the rule.
BTW Microsoft Azure Storage Explorer in my case showed only some subset of folders which is much worse than displaying duplicated directories so I switched to Azure Explorer mentioned above and it's worth recommending.
I was experiencing an issue where the "folder" names appeared identical, but on closer inspection one had a trailing space.
Because folders don't really exist in blob storage and a space is a valid value, it is possible to have trailing or leading spaces in the names.
Azure blob storage does not ahve the concept of folder, only container, you can simulate folder setting the name of the blog to save like 'folder/img.png', but folder/ is part of the name of the blob.
Also, I ever use Storage Explorer, try with this: http://azurestorageexplorer.codeplex.com/releases/view/125870
I have a trivial and simple task - I want to store some my data (documents, photos etc) on Azure as backup. Which type of service should I select? Store as Blob? But I want to save a structure of data (folders, subfolders etc). Azure Backup? It stores only archive data, I don't want to archive it all in one. DocumentDB? I not need to have features like return json format etc... What is the best way to store many (thousands) files (big and small) to save folder structure without archivation to one file (so, I want to have a simple way to get only one file quickly)
I use Windows 7.
In addition to what knightpfhor wrote above you might also want to take a look at Getting Started with AzCopy - it is a Windows tool that helps you copy content to / from your local storage to Blob Storage. PowerShell and XPlatCLI are other options as well.
Based on what you've described, blob storage can achieve what you're after. While blob storage doesn't technically support folders, it does let you include \ in the file names which are interpreted by some blob storage clients as folders (for example the free Cerebrata Azure Explorer). So if you have
RootDrive
|
--My Pictures
|
Picture1.jpg
Picture2.jpg
--My Other Picutres
|
Picture1.jpg
You could create blobs with the names:
RootDrive\My Pictures\Picture1.jpg
RootDrive\My Pictures\Picture2.jpg
RootDrive\My Other Picutres\Picture1.jpg
And they have the ability to be interpreted as folders.
I examined Recovery Services deeply and it works now (from december 2014) for Windows client versions too (including Windows 7, Windows 8, Windows 8.1). It allows to backup selected files and folders.
This is a guide how to use it
http://azure.microsoft.com/blog/2014/11/04/back-up-your-data-to-the-cloud-with-3-simple-steps/