I am trying to deploy my flask app on Microsoft Azure. On the deployed site it can read the db fine, but whenever I try to write to the db, it gives: sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) database is locked
My file structure inside the app folder is:
templates
app.py
db.sqlite
However when i run it on my local, everything works fine. Any ideas how I can solve this?
Run from Package makes wwwroot read-only, and you will receive an error when writing files to this directory. You may refer to below links might be helpful:
https://github.com/Azure/app-service-announcements/issues/84
https://learn.microsoft.com/en-us/azure/azure-functions/run-functions-from-deployment-package
There is not more information for us to help fixing your issue, such as the necessary code and configuration for using SQLAlchemy with SQLite.
So I suggest that you can carefully refer to the some topics about SQLite locked file for writing.
Database Locking Behavior / Concurrency
The items Client/Server Applications and High Concurrency of the section Situations Where A Client/Server RDBMS May Work Better in the SQLite offical page Appropriate Uses For SQLite.
Meanwhile, some existing SO threads may will help you.
sqlite3.OperationalError: database is locked
SQLAlchemy and SQLite: database is locked
Hope it helps. If you can update your description to post more helpful information, I will try to reproduce your issue and fix it, and then update my post.
Related
I'm using flask on appfog.com to make a personal blog. Today I tried to use sqlite. I can run the application locally with sqlite but when I update the app to AppFog, it does not seem to work. I can't find how to use sqlite in AppFog's docs. Can anyone tell me?
Thanks...
Sorry for my poor english:-)
It's not recommended to use sqlite for your production apps on AppFog because the file storage is ephemeral. Every time you update your app the database will get blown away. You're better off creating and binding a postgres, mysql, or mongodb database service for your app. You can continue to use sqlite db locally but your production app will use the bound service.
See the Bind Service section of: https://docs.appfog.com/languages/python/flask
I'm in need of some help in developing a desktop application with a pre-populated database. I have tried numerous ways to get this working including those mentioned on both Tidesdk's API here http://tidesdk.multipart.net/docs/user-dev/generated/#!/api/Ti.Database.DB and at Titanium Desktops old API here http://developer.appcelerator.com/apidoc/desktop/latest/Titanium.Database-module.
While the later (using Titanium not Ti) works in creating a database in the apps directory it does not install my pre-populated sqlite database which is located in the resources file of my app.
A couple of my attempts located below
var db = Titanium.Database.openFile('test_db.sqlite', 'test_db');
var db = Titanium.Database.openFile(Ti.Filesystem.getFile(
Ti.Filesystem.getApplicationDataDirectory(), 'test_db.sqlite'));
var db = Ti.Database.open('test_db');
As stated most of these manage to create a database with the name given but when trying to run something as simple as a db.execute(SELECT) of something I know would exist in my pre-populated db I receive an error stating
Exception executing: SELECT name, id FROM people ORDER BY name COLLATE NOCASE, Error was: SQL Statement invalid or database missing
I have searched high and low for something to answer this but everyone continues to refer to the aforementioned API's or to the Mobile API's Ti.database.install() which does not work either.
Is it possible with titanium desktop to use a pre-populated sqlite database or do I have to populate it after I create it? If so any direction would be helpful (where to place the .sqlite file in the app and what functions to call).
I am currently using Titanium Studio with a titanium desktop osx SDK of 1.2.0.RC4 as requested by tidesdk.org until they have released there open source sdk.
Thanks in advance
This is possible, I just used this feature in a recent desktop app, deployed it successfully to Windows and Mac.
In my experience, sometimes your database file can be corrupted, for example if you use the Titanium.Database.install command, and it cant find the file to preload from (maybe the first time you specified the path wrong for instance), it will create the file itself, any subsequent install commands will not work because it already thinks this database has been installed.
Have you tried clearing out the application data? This is where titanium installs the database. For Mac this is in your /User/Library/Application Support/APPNAME directory. Their is a directory for databases, delete this and try again.
Also, this answer on Titanium Q&A may help, it talks about the process with the Mobile SDK but the Database stuff is the same.
Hope this helps!
I have been using a central MS SQL database located in the cloud to develop a web site project. I have recently found myself in situations, when I need to develop without the internet connection. I want to begin to use a locally available copy of the existing database, put it in App_Data folder.
What is the correct set of steps I need to undertake to get the project to work with local DB?
For example:
Detach a db from an existing SQL instance.
Copy to a development machine.
etc.
Moving a SQL-Server DB is not that hard. Look here for some methods to do it.
http://support.microsoft.com/kb/314546
I usually find the sp_detach + sp_attach method really easy.
I would create an empty shell database locally, then use one of the many schema comparison solutions available to make the local database look exactly like the cloud database.
Correct way is to create and regularly update your standalone copy of database using import/export. In particular MS SQL Server provides Import/Export Wizard tool for such purpose.
Make a backup
Copy backup file
Restore on your server
Restore/organise users
I am publishing an AIR app in debug mode using FlashDevelop and have included a database in the files/folders to be published.
When the app first launches it checks whether there is an instance of this db in the applicationStorageDirectory, if there isn't it copies the included one from the applicationDirectory to the applicationStorageDirectory.
This should mean that the referenced database dbFile = File.applicationStorageDirectory.resolvePath(DB_FILE_NAME); should now be writable, however when i run the app i can read the records from the table but when i attempt to write using an SQL statement I get an SQLError: 'Error #3122: Attempt to write a readonly database'.
I know that this would be thrown if i was attempting to write to the read only location of the applicationDirectory but i'm certainly using the File.applicationStorageDirectory location which should (as far as i know) be writable.
The location of the db on my Windows 7, 64bit = C:\Users\sean.duffy\AppData\Roaming\FishFightAppData\Local Store\db this is found using the dbFile.nativePath property so again i'm sure i should be able to update the db.
Anyone got any ideas? I have tried everything i could think of and searched all over but the only common cause seems to be when people try to write to the asplicationDirectory and not the storage directory....
UPDATE::
My bad - have just realised that i've misread the API of the 3rd party library i'm using! I should have been calling executeModify(statement) which can modify the contents of the db, instead i'm calling execute(statement) which doesn't/can't overwrite the db.
The source code is compiled into a swc and there was no documentation to point out you needed to use executeModify, although i should have guessed from the name i suppose!
Sorry about that and thanks for your help
(As a public courtesy to get this off the unanswered list, I am reposting the apparent solution. As usual, the asker is more than welcome to ignore mine and post it themselves and accept their own answer.)
In this API, you need to call executeModify(statement), not execute(statement). The latter does not overwrite the database.
I'm building a web application which soon I'll be promoting to production. This application has a login screen, as you know I used the integrated DB for developing. Now I want to move this database to a full SQL Server 2005. I'm using the aspnet_regsql.exe to create my membership tables and stored procedures in the SQL Server 2005 but I'm getting an error:
An error occurred during the execution of the SQL file 'InstallMembership.sql'. The SQL error number is 207 and the SqlException message is: Invalid column name 'FailedPasswordAnswerAttemptWindowStart'.
I google this for half of the day already and I can't seem to fine what's wrong, does anybody have ANY ideas on what am I doing wrong here? Any help will be really appreciate it.
The easiest way to deploy a brand new database to a remote server is to just publish the database from within Visual Studio. Once you do that you have the scheme and data all in one script. You then access your server either via a local SQL manager connection or a remote manager and run the script on your remote database.
The site 4GuysFromRolla has a nice little walk through with graphics which describe how to accomplish the publishing of your local database to your hosted one.
Good luck, and hope this helps you out some.
Go through the *.sql script file and see where that column reference is. Then you'll be able to see what exactly the script is doing to cause this error. My guess would be that it is getting caught up on referential integrity. If it is trying to create a foreign key constraint that that table/column does not exist then you'll see that error.
But back to the original question at hand. You don't need to recreate your whole database. That script file is to lay down the Membership for an empty database. If you have a working dev database you can just back it up and restore it to a production instance. No need to rebuild the membership database objects.