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
Related
My ASP.NET Core Rest API is returning a 500 Internal Server Error on post method while adding a new customer. I am able to get data from my development database, but myDbContext.SaveChanges(); failed saying my development user doesn't have access to the main database, but my connection string refers to my development database only.
My database name : MyappDbDev
My database user : AppUserDev
Error:
The server principal "AppUserDev" is not able to access the database "MyappDbDev" under the current security context
I have another database in production with following credentials:
Database name : MyappDb
Database user : AppUser
I didn't find any useful suggestions after researching for days, at last I found that I had a trigger for the table that I am adding new record.
which the trigger had insert command to old database.
It was a silly mistake , but I hope this may help someone someday.
I have created an SQLDB service instance and bound it to my application. I have created some tables and need to load data into them. If I write an INSERT statement into RUN DDL, I receive a SQL -104 error. How can I INSERT SQL into my SQLDB service instance.
If you're needing to run your SQL from an application then there are several examples (sample code included) of how to accomplish this at the site listed below:
http://www.ng.bluemix.net/docs/services/SQLDB/index.html#run-a-query-in-java
Additionally, you can execute SQL in the SQL Database Console by navigating to Manage -> Work with Database Objects. More information can be found here:
http://www.ng.bluemix.net/docs/services/SQLDB/index.html#sqldb_005
s.executeUpdate("CREATE TABLE MYLIBRARY.MYTABLE (NAME VARCHAR(20), ID INTEGER)");
s.executeUpdate("INSERT INTO MYLIBRARY.MYTABLE (NAME, ID) VALUES ('BlueMix', 123)");
Full Code
Most people do initial database population or migrations when they deploy their application. Often these database commands are programming language specific. The poster didn't include the programming language. You can accomplish this two ways.
Append a bash script that would call your database scripts that you uploaded. This project shows how you can call that bash script from within your manifest file as part of doing a CF Push.
Some languages like offer a file type or service that will automatically get used to populate the database on initial deploy or when your migrate/synch the db. For example Python Django offers a "fixtures" file that will automatically take a JSON file and populate your database tables
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.
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.
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.