The application I develop is deployed to severeal environments (development, test, staging, production).
While developing I created the entity model from the existing development-database. Everything works fine, but as I wanted to put the application onto the test-environment, I realized the following problem:
The structure of the database is identical in all environments, but the database schema changes from environment to environment. For example there's a Customers table in every database. On my local dev machine it has the schema dbo ([dbo].[Customers]), but in the test environment the schema is test ([test].[Customers]), whilst the schema is stag in the staging environment ([stag].[Customers]) and so forth.
So when I deploy the application in the test environment, it gets no data from the database, because the entity framework expects the data to be found in [dbo].[Customers] but there is no such table, there is just a [test].[Customers].
I know, that I can define a schema other than dbo, but this doesn't help me, because I need a different schema depending on the deployment environment.
Any suggestions?
Somehow I think I'll be ending up, asking my DB admin to change the schema to dbo in every database in each environment...
If you are using code first you have to use fluent API approach from linked question and load current schema from configuration file (you will have to modify configuration per each deployment).
If you are using ObjectContext with EDMX you can use Model adapter. Other way which works with DbContext as well is storing EF metadata in files and executing some code which will change schema in ssdl file at application startup.
Related
I'm new at prisma 2 but have got a database working. I have used prisma 'init' and 'migrate dev' to create database tables for my model and can interact with the database using the Prisma client - prisma 2.22.1
Usually for a project, I'd have dev, test and prod environments and use env-cmd to set the relevant differences, e.g. connection details for getting to the database.
With prisma 2 however, it seems like there's a single .env file that is used for the database connection details, so I cannot see how to proceed for the different environments.
Note that I'm not meaning different types of database - in this example all are postgresql.
I can see possibilities for getting past this hurdle, for example for the script to write a suitable .env file according to the required environment as part of running the app, but 'not ideal' really doesn't give this idea the review that it deserves. Or getting more computers.
Any suggestions please for using different databases from the same project? Am I missing something basic or is it deliberately blocked?
I developed a website using spring boot in this application I'm using architecture multi tenant to manage my database.
The database on the host got filled with critical data and it still grows. Now I want to add new columns to different tables and also add new tables. The problem that I face, it is how to update the last modification on each schema without losing any data.
Ps: I'm using hibernate for creating new schema.
Ps : the new schema is created when a new user create a new account in the website
You shouldn't use Hibernate for that task.
The migrate the database Flyway or Liquibase should be used:
https://flywaydb.org/
https://www.liquibase.org/
Both libaries are very well integrated in Spring Boot as well:
https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#howto-use-a-higher-level-database-migration-tool
I have two folders for my migrations (AuthContext and UserProfileContext), each has their own migration and some custom sql to run afterwards for data migrations and whatnot.
This works fine when using package manager console. I
Restore from production
Run Update-Database -ConfigurationTypeName Migrations.Auth.Configuration
Run Update-Database -ConfigurationTypeName Migrations.UserProfile.Configuration
Then everything is very happy in the new database, migrations executed data shuffled where it needs to.
I tried to test out the migrations on publish piece by:
Restore production on dev database
Single connection string (all contexts use the same) pointed to dev database
Publish to azure web site
Checked the box for Apply Code First Migrations
Selected that single connection string
Okay it published fine; however, when I went to look at the database, nothing happened! It did not create the necessary tables, columns, or data moves.
TLDR; Code first migrations are not running after publish to Azure
Update 1
I've tried any combination of the below: only one single connection string so I'm guessing that's not the issue, and execute migrations is checked.
On publish the api runs but no database changes are made. I thought perhaps I needed to hit it first but I just get random errors when I try to use the api (which now of course relies on the new database setup), and the database is still not changed.
I've seen a couple references out there about needing to add something to my Startup class but I'm not sure how to proceed.
Update 2
I solved one issue by added "Persist Security Info=True" to my connection string. Now it actually connects to the database and calls my API; however, no migrations are running.
I attached debugger to Azure dev environment and stepped through... on my first database call it steps into the Configuration class for the Migration in question, then barfs and I can't track down the error.
public Configuration()
{
AutomaticMigrationsEnabled = false;
MigrationsDirectory = #"Migrations\Auth";
ContextKey = "AuthContext";
}
Update 3
Okay, dug down and the first time it hits the database we're erroring. Yes this makes sense since the model has changed, but I have migrations in place, enabled, and checked! Again, it works fine when running "Update-Database" from package manager console, but not when using Execute Code First Migrations during publish to Azure
The model backing the 'AuthContext' context has changed since the
database was created. Consider using Code First Migrations to update
the database (http://go.microsoft.com/fwlink/?LinkId=238269).
Update 4
Okay I found the root issue here. VS is setting up the additional web.config attrib for databaseInitializer on only one of my database contexts, the one not mentioned is in fact hit first from my app.
So now I have to figure out how to get it to include multiple contexts, or, combine all of my stuff into a single context.
The answer to this post is not very detailed.
This article explains what I had to do to fix a similar problem to this:
https://blogs.msdn.microsoft.com/webdev/2014/04/08/ef-code-first-migrations-deployment-to-an-azure-cloud-service/
I'll roughly describe the steps I had to take below:
Step 1
Add your connection strings to your dbContexts, in my situation, they were both the same.
Step 2
Add this to your web.config
<appSettings>
<add key="MigrateDatabaseToLatestVersion" value="true"/>
</appSettings>
Step 3
And add this to the bottom of your global.asax.cs / Startup.cs(OWIN startup)
var configuration = new Migrations.Configuration();
var migrator = new DbMigrator(configuration);
migrator.Update();
Solved! To summarize the solution for posterity:
Enable Code First Migrations only enables them for one base connection string per checkbox checked, regardless of how many contexts have migrations against that base connection string. So in my case I broke out the two in question into two different connection strings.
Then I was hitting other errors and identified that if you're changing the base connection string to the model backing asp identity you need to include (one time publish) the additional flag base("AuthContext" , throwIfV1Schema: false)
For anyone who has this issue and may have overlooked the following: be sure to check that you have correctly set the connection string in your Web.config file and/or Application settings on Azure. This includes DefaultConnection and DefaultConnection_DatabasePublish.
In our case the former was correct but the latter contained the wrong database instance because it had been carried over from an App Service clone operation. Therefore the wrong database was being migrated.
If I have an EF6 Code First environment in need of a schema change, is it possible to configure it in such a way that I can apply the migration (via Update-Database -Script) before the code gets deployed?
I just ran a simple test with a console app building a DB with migration "Initial", taking a copy of the application at this point. I then modified the schema by adding a new property to my entity and added a "V2" migration and ran Update-Database. When trying to run the "old" code against this migrated DB, I get an InvalidOperationException "The model backing the context has changed since the database was created."
Is the Continuous Delivery type operation where you might want one server running new application code with others running old versions possible with EF code first?
can you modify old code ?
if yes disabling schema checking in old code is an option.
btw: Are you sure the added column is nullable or as a default value ?
to avoid surprises, you can also use a connection string that has read only rights on the schema to avoid data corruption.
I cannot get the Entity Framework to work against SQL Azure. Is this just me or is it not intended to be compatible? (I have tried the original release of EF with VS2008 as well as the more recent VS2010 Beta 2 version)
To check this I created the simplest scenario possible. Add a single table to a local SQL Server 2008 instance. The table has two columns, a primary key of type integer and a string column. I add a single row to the table with values of (1, foobar). I then added exactly the same setup to my SQL Azure database.
Created a console application and generated an EF model from the local database. Run the application and all is good, the single row can be returned from a trivial query. Update the connection string to connect to the SQL Azure and now it fails. It connects to the SQL Azure database without problems but the query fails on processing the result.
I tracked the initial problem down using the exception information. The conceptual model had the attribute Schema="dbo" set for the entity set of my single defined entity. I removed this attribute and now it fails with another error...
"Invalid object name 'testModelStoreContainer.Test'."
Where 'Test' is of course the name of the entity I have defined and so it looks like it's trying to create the entity from the returned result. But for some unknown reason cannot work out this trivial scenario.
So either I am making a really fundamental error or SQL Azure is not compatible with the EF? And that seems just crazy to me. I want to use the EF in my WebRole and then RIA Services to the Silverlight client end.
While I haven't done this myself I'm pretty sure that members on the EF team have, as has Kevin Hoffman.
So it is probably just that you went astray with one step in your porting process.
It sounds like you tried to update the EDMX (XML) by hand, from one that works against a local database.
If you do this most of the changes will be required in the StorageModel element in the EDMX (aka SSDL). But it sounds like you've been making changes in the ConceptualModel (aka CSDL) element.
My guess is you simply need to replace all references to the dbo schema in the SSDL with whatever schema is the SQL Azure schema.
Hope this helps
Alex
To answer the main question - Yes, at least the Entity Framework v4 can be used with SQL Azure - I haven't honestly tried with the initial version (from the .Net Framework 3.5. SP 1).
A little while back I did a complete project and blogged about the experience: http://www.sanderstechnology.com/?p=9961 Hopefully this might help a little bit!
Microsoft's Windows Azure documentation contains How to: Connect to Windows Azure SQL Database Using the ADO.NET Entity Framework.
After creating your model, these instructions describe how to use SQL Azure with the Entity Framework:
Migrate the School database to SQL Database by following the instructions in How to: Migrate a Database by Using the Generate Scripts Wizard (Windows Azure SQL Database).
In the SchoolEFApplication project, open the App.Config file. Change the connection string so that it connects to your SQL Database.
<connectionStrings>
<add name="SchoolEntities"
connectionString="metadata=res://*/SchoolDataModel.csdl|res://*/SchoolDataModel.ssdl|res://*/SchoolDataModel.msl;provider=System.Data.SqlClient;provider connection string="Data Source=<provideServerName>.database.windows.net;Initial Catalog=School;Integrated Security=False;User ID=<provideUserID>;Password=<providePassword>;MultipleActiveResultSets=True;Encrypt=True;TrustServerCertificate=False""
providerName="System.Data.EntityClient"/>
</connectionStrings>
Press F5 to run the application against your SQL Database.