C# Discussion Boards - CodeProject

Re: My winform resize when i open an OleDbConnection

Pete O'Hanlon27-Nov-22 21:30

27-Nov-22 21:30

Inherently, there's nothing in there that would cause the UI to resize. I assume, however, that there is a lot more to your code than this - what do you do with the DataTable? Is this being bound to something on the form?

Advanced TypeScript Programming Projects

Concurrent Containers

Richard Andrew x6424-Nov-22 14:47

Richard Andrew x64

24-Nov-22 14:47

I know about the ConcurrentBag, ConcurrentDictionary, ConcurrentQueue and ConcurrentStack collection classes. But is there any Concurrent equivalent to the good ol' List<>?

The ConcurrentBag says it provides a thread safe unordered collection, but I need an ordered collection.

The difficult we do right away...
...the impossible takes slightly longer.

Re: Concurrent Containers

Richard Deeming24-Nov-22 22:02

Richard Deeming

24-Nov-22 22:02

There's a discussion about adding a concurrent list here:
ConcurrentList<T> · Issue #41740 · dotnet/runtime · GitHub[^]

The conclusion is that there's no meaningful way to implement it without locking the entire list - at which point, you might was well wrap a regular List<T> with locks.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Re: Concurrent Containers

Richard Andrew x6425-Nov-22 2:18

Richard Andrew x64

25-Nov-22 2:18

Thank you for the reply, Richard.

The difficult we do right away...
...the impossible takes slightly longer.

Re: Concurrent Containers

Gerry Schmitz25-Nov-22 5:10

Gerry Schmitz

25-Nov-22 5:10

A concurrent dictionary loaded ordered is essentially an ordered list.

Whether you handle it as KeyValue pairs or as .Values is another matter (maybe).

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

Re: Concurrent Containers

Richard Andrew x6425-Nov-22 5:24

Richard Andrew x64

25-Nov-22 5:24

Yeah, that's what I've settled on doing - using ConcurrentDictionary's.

Thanks for your reply. Smile | :)

The difficult we do right away...
...the impossible takes slightly longer.

Entity Framework Core 6 Problem

Kevin Marois24-Nov-22 9:01

Kevin Marois

24-Nov-22 9:01

I'm using EF 6 Core Code First. I'm trying to set up some basic code and I'm getting an exception at runtime.

Here's my Context class:

using Microsoft.EntityFrameworkCore;

namespace EFCoreDBFirstExample.Models
{
    public partial class ModelContext : DbContext
    {
        public virtual DbSet Departments { get; set; }
        public virtual DbSet Employees { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            var connectionString = @"Server=MAROIS_KEVIN_1\SQLEXPRESS;Database=Test;Trusted_Connection=true;Encrypt=false;";
            optionsBuilder.UseSqlServer(connectionString, options => options.EnableRetryOnFailure());
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity(entity =>
            {
                entity.ToTable("Departments", "public");

                entity.HasKey(e => e.DepartmentId)
                      .HasName("DeptartmentId");

                entity.Property(e => e.DepartmentId)
                      .HasColumnName("DeptartmentId");

                entity.Property(e => e.DepartmentName)
                    .HasColumnName("DepartmentName")
                    .HasColumnType("varchar")
                    .HasMaxLength(30);
            });

            modelBuilder.Entity(entity =>
            {
                entity.ToTable("EmployeeName", "public");

                entity.HasKey(e => e.EmployeeId)
                      .HasName("EmployeeId");

                entity.Property(e => e.EmployeeId)
                      .HasColumnName("EmployeeId");

                entity.Property(e => e.EmployeeName)
                    .HasColumnName("EmployeeName")
                    .HasColumnType("varchar")
                    .HasMaxLength(30);
            });
        }
    }
}

Here's how I'm using it

using EFCoreDBFirstExample.Models;

using (var db = new ModelContext())
{
    // Creating a new department and save it to the database
    var newDept = new Departments();
    newDept.DepartmentId = 1;
    newDept.DepartmentName = "Development";

    db.Departments.Add(newDept);
    var count = db.SaveChanges(); //<======================= ERROR HERE

    Console.WriteLine("{0} records saved to database", count);

    // Retrieve and display the data
    Console.WriteLine();
    Console.WriteLine("Departments:");
    foreach (var dept in db.Departments)
    {
        Console.WriteLine($"{dept.DepartmentId}: {dept.DepartmentName}" );
    }

    Console.ReadLine();
}

Here's the exception:

Microsoft.EntityFrameworkCore.Storage.RetryLimitExceededException
  HResult=0x80131500
  Message=The maximum number of retries (6) was exceeded while executing database operations with 'SqlServerRetryingExecutionStrategy'. See the inner exception for the most recent failure.

Inner Exception 1:
SqlException: Cannot open database "Test" requested by the login. The login failed.
Login failed for user 'MAROIS_KEVIN_1\kevin'.

As you can see, I'm using Trusted Connection in my connection string. Not sure why EF is trying to connect with the user 'kevin'.

I could use some help here. Thanks

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.