C#•12mo ago

EF6+.NET Framework+ Postgre issue

Maybe the title is confusing but i need help, i want a really basic code first app. I researched 3 days but i can't find any solution to this problem. When i try to enable-migrations PMC gives me this error. I can share my codes if you want. My connectionString is true.So don't ask me this please.

An error occurred accessing the database. This usually means that the connection to the database failed. Check that the connection string is correct and that the appropriate DbContext constructor is being used to specify it or find it in the application's config file. See http://go.microsoft.com/fwlink/?LinkId=386386 for information on DbContext and connections. See the inner exception for details of the failure.

An error occurred accessing the database. This usually means that the connection to the database failed. Check that the connection string is correct and that the appropriate DbContext constructor is being used to specify it or find it in the application's config file. See http://go.microsoft.com/fwlink/?LinkId=386386 for information on DbContext and connections. See the inner exception for details of the failure.

32 Replies

Angius•12mo ago

Seeing the code would be nice, yes Also, ensure Postgres is actually running

candrdOP•12mo ago

Postgres is running, my java db is working rn Kisiler.cs

 
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RehberAppNew
{
    public class Kisiler
    {
        [Key]
        public int Id { get; set; }
        public string Name { get; set; }
        public string Surname { get; set; } 
        public int Number { get; set; }
    }
}

 
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RehberAppNew
{
    public class Kisiler
    {
        [Key]
        public int Id { get; set; }
        public string Name { get; set; }
        public string Surname { get; set; } 
        public int Number { get; set; }
    }
}

Jimmacle•12mo ago

your dbcontext registration/instantiation is the important part here

candrdOP•12mo ago

AppContext.cs

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RehberAppNew
{
    public class AppContext : DbContext
    {
        AppContext(): base("Name=AppContext") { }
        DbSet<Kisiler> Kisilers { get; set; } 
    }
}

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RehberAppNew
{
    public class AppContext : DbContext
    {
        AppContext(): base("Name=AppContext") { }
        DbSet<Kisiler> Kisilers { get; set; } 
    }
}

Jimmacle•12mo ago

so where is the dbcontext getting the connection string from? or is old EF weird and magic about how it works

candrdOP•12mo ago

App.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" requirePermission="false" />
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.8.1" />
  </startup>
  <entityFramework>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
      <provider invariantName="Npgsql" type="Npgsql.NpgsqlServices, EntityFramework6.Npgsql" />
    </providers>
    <defaultConnectionFactory type="Npgsql.NpgsqlConnectionFactory, EntityFramework6.Npgsql" />
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <add name="Npgsql Provider" invariant="Npgsql" description=".NET Framework Data Provider for PostgreSQL" type="Npgsql.NpgsqlFactory, Npgsql, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    </DbProviderFactories>
  </system.data>
  <connectionStrings>
    <add name="AppContext" providerName="Npgsql" connectionString="Server=localhost;Database=directory;User Id= postgres;Password=pst.grs" />
  </connectionStrings>
</configuration>

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" requirePermission="false" />
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.8.1" />
  </startup>
  <entityFramework>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
      <provider invariantName="Npgsql" type="Npgsql.NpgsqlServices, EntityFramework6.Npgsql" />
    </providers>
    <defaultConnectionFactory type="Npgsql.NpgsqlConnectionFactory, EntityFramework6.Npgsql" />
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <add name="Npgsql Provider" invariant="Npgsql" description=".NET Framework Data Provider for PostgreSQL" type="Npgsql.NpgsqlFactory, Npgsql, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
    </DbProviderFactories>
  </system.data>
  <connectionStrings>
    <add name="AppContext" providerName="Npgsql" connectionString="Server=localhost;Database=directory;User Id= postgres;Password=pst.grs" />
  </connectionStrings>
</configuration>

Jimmacle•12mo ago

i have to ask, is there a reason you're using such an outdated version of .NET?

candrdOP•12mo ago

app.config

Angius•12mo ago

Ah, it's 4.8 I know nothing about it, so you'll have to rely on our resident archaeologists for help lol

candrdOP•12mo ago

how can i use in winform application otherwise?

Jimmacle•12mo ago

you can use winforms in .NET 8

candrdOP•12mo ago

wait a second how?

Angius•12mo ago

Unless you mean webforms

Jimmacle•12mo ago

i personally wouldn't, but there's nothing stopping you

Angius•12mo ago

dotnet new winforms

Jimmacle•12mo ago

<UseWindowsForms>true</UseWindowsForms> in your csproj or that

Angius•12mo ago

Or $newproject

MODiX•12mo ago

When creating a new project, prefer using .NET over .NET Framework, unless you have a very specific reason to be using .NET Framework. .NET Framework is now legacy code and only get security fix updates, it no longer gets new features and is not recommended. https://cdn.discordapp.com/attachments/569261465463160900/899381236617855016/unknown.png

Jimmacle•12mo ago

that would be another whole tier of issue

Angius•12mo ago

Winforms are old, yes, but still supported Webforms are dead, and good riddance

Jimmacle•12mo ago

well not the ones running at my job

Angius•12mo ago

https://tenor.com/view/crab-rave-dancing-dancing-crab-gif-16543314

Tenor

Jimmacle•12mo ago

Angius•12mo ago

My condolences

candrdOP•12mo ago

actually i made with mvc model but i have to made with with windows forms So can i work with efcore in .net 8 ?

Angius•12mo ago

Of course

candrdOP•12mo ago

i can't see any config file here? how can i add connectionstring to my project for npgsql?

Angius•12mo ago

https://stackoverflow.com/a/65675178/6042255 this could be of help

Jimmacle•12mo ago

ef core is more flexible, as long as you can get it a DbContextOptions<MyDbContext> with the connection information it'll just work or hardcode it in the context if you're just doing basic testing

Jimmacle•12mo ago

https://learn.microsoft.com/en-us/ef/core/get-started/overview/first-app?tabs=netcore-cli

Getting Started - EF Core

Getting started tutorial for Entity Framework Core

candrdOP•12mo ago

Thanks to everyone who tried to help me

candrdOP•12mo ago

Now this is

Gaming

Programming

EF6+.NET Framework+ Postgre issue

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