Managing transactions using ADO.Net Entity framework - Update multiple databases - entity-framework

I need to update multiple databases in one transaction using entity framework. Means if we need to insert records in two tables of two different databases and insertion succeeds for first database but fails for other database then insertion in first database should also get rolled back.
Please let me know if we can do this using entity framework.
Thanks
Sharad Rastogi

Managing Connections and Transactions (Entity Framework)
You can use a TransactionScope to accomplish what you require.
How to: Manage Transactions in the Entity Framework
TransactionScope and ADO.NET Entity Framework

Related

How to create DB Context run time?

In my asp.net core application, each client has their own database schema.
Hence there are many databases. Sometimes the tables and fields will be different.
I have used Entity Framework core as ORM and we are following Generic Repository pattern.
Is there any option to generate DB Context at run time corresponding to each client?
Thanks
Krishnan

Is there Entity Framework support for saving to multiple databases on the same SQL Server in single transaction?

I have two databases on the same SQL Server instance. I would like to write a record to each database in a single transaction.
In Linq-to-SQL, I would connect to either database with one context and use three part naming to identify the tables.
Is there a similar capability in Entity Framework?
I'm trying to avoid DTC, it has been forbidden - so the usual TransactionScope approach is not available to me.
There is not a way I know of... you could potentially use the UnitOfWork pattern
http://www.codeproject.com/Articles/581487/Unit-of-Work-Design-Pattern
That might allow you to at least go back to the other Db and un-commit?
Personally I think your going to struggle.

Modifying the table in the database without loosing the data using database first approach, Entity Framework

Is there a way to add/delete columns in the database using database-first approach in Entity Framework? I know we can do this by doing code-first approach.

Using JPA and JDBC together

In my project, we are upgrading an old J2EE application to Java EE 6.
Since the business logic is quite complex, we want to retain the EJB + DAO code as much as possible. The old code uses plain JDBC for database persistence.
But in our new/upgraded application, we plan to use JPA.
We would like to use JPA for all the read operations on database and use JDBC for the writes (inserts/updates/deletes). Is this possible in the same transaction?
For example:
obtain an Entity Manager reference and read an employee record from the database (employee entity) using entity manager find (or a named query)
convert the entity instance to a POJO
update the POJO
perform some business logic on the POJO (reuse old code as-is)
create a JDBC connection and use a prepared statement to update the employee record in database (reuse old code as-is)
Questions:
If I open 2 separate connections to the database - one from JPA and another from JDBC, will it still be in the same transaction (since app server manages the JTA transaction)?
What are the potential issues with this approach?
Since I am updating the database via JDBC, the entity in persistence context will not be in sync with the database. How to handle caching in such cases?
I looked at the following related threads, but I would like to know more in detail.
Combining JPA and JDBC actions in one transaction
Hibernate and JDBC in one transaction

Entity Framework Multi-Tenant (Single database Multiple Schema) With Code First Migration

We have created Entity Framework Multi-Tenant (Single database Multiple Schema) With Code First like in this example http://romiller.com/2011/05/23/ef-4-1-multi-tenant-with-code-first/. Our database is live. Now we are facing very serious problem. We need some changes in our entity. The question is that how we update our database for each schema table. Is there possible Migration in current scenario?