I need to do CRUD operations on two separate databases (on two separate on-premise servers) within ONE transaction. All database changes should be rolled back completely if any stored procedure or CRUD operation in the transaction fails. I was told to use TransactionScope , and that distributed transactions are not supported (which is true; I got an error "distributed transactions are not supported on this platform" when I tried using TransactionScope ).

However, I just tried nested regular transactions as shown in the code below, and it did everything I wanted. Curious to know:

• Why does this work correctly? What am I not understanding?
• Is the code correct for my purposes? Should I be wary of any edge cases?

// DbContexts for my 2 DBs dependency-injected
MyFirstDB _my1st_DbContext;
MySecondDB _my2nd_DbContext;
...
MyFirstDB _my1st_DbContext;
MySecondDB _my2nd_DbContext;
...
public async Task ExecuteOperations()
{
    var secondTransac = _my2nd_DbContext.Database.BeginTransaction()

    using (var firstTransac = _my1st_DbContext.Database.BeginTransaction()) 
    {
        try
        {
            await _my1st_DB_StoredProcService.GenerateStudentRecord();
 
            await _my1st_DbContext.AnimalTable.AddAsync(new Animal{Name="McDogFace"});
            await _my1st_DbContext.SaveChangesAsync();

            using (secondTransac)
            {
                await _my2nd_DbContext.VehicleTable.AddAsync(new Vehicle { Brand = "BMW" });
                await _my2nd_DbContext.SaveChangesAsync();

                // This stored procedure throws an error to roll back
                // all the DB operations done so far on both DBs
                // Note: This is a call to a my1st_DB stored proc
                await _my1st_DB_StoredProcService.GenerateEmployeeRecord();

                await secondTransac.CommitAsync();
            }
      
            await firstTransac.CommitAsync();
        }
        catch (Exception ex) 
        {
            await firstTransac.RollbackAsync();
            await secondTransac.RollbackAsync();
            throw ex.InnerException ?? new Exception(ex.Message);
        }
    }
}