Entity Framework Core: How to get the Connection from the DbContext?

Question

I am trying the new Entity Framework Core with MySQL Connector.

I can get a valid DbContext and write into the database so everything has been setup correctly.

I need to get the Connection from the DbContext because I have to test for it at application starting using a connection.Open() inside a try statement. If there is not a valid connection, the console app should try to start MySQL Server and retry.

How can I get the Connection from the DbContext?

Before EF6 by context.Connection. After EF6 by context.Database.Connection.

It seems the latest has been removed too from EFCore.

Solution 1

The Microsoft.EntityFrameworkCore.Relational (https://www.nuget.org/packages/Microsoft.EntityFrameworkCore.Relational/) package provides extension methods for this - you can use dbContext.Database.OpenConnection() or dbContext.Database.GetDbConnection() to get the DbConnection object.

Note: if you have Microsoft.EntityFrameworkCore.SqlServer installed then you don't have to explicitly install this package

Solution 2

You can do the following :

1. If you are using System.Data.SqlClient change it to Microsoft.Data.SqlCLient since the later library will accept excplicit casting from the object of the DBContext in both EntityFramework and EntityFrameWorkCore.
2. Create a command from the DBContext connection and Cast it to your SQLCommand by

using (SqlCommand cmd = (SqlCommand)database.GetDbConnection().CreateCommand())

3. Check the connection state and open it if necessary.

if (cmd.Connection.State != ConnectionState.Open)
{
    cmd.Connection.Open();
}

4. If there is a transaction in the DBContext add it to the command.

if (database.CurrentTransaction != null)
{
    cmd.Transaction = database.CurrentTransaction.GetDbTransaction();
}

By doing this you will avoid any problems can appear when using comands outside the context.