How to Install pgAdmin4 on Ubuntu 20.04/18.04/16.04?. This post has been written primarily to guide new users on installing pgAdmin 4 on Ubuntu 20.04/18.04/16.04. pgAdmin is a feature-rich and open source PostgreSQL administration and development platform that runs on Linux, Unix, Mac OS X, and Windows.
With pgAdmin you can manage PostgreSQL database servers, from version 9.2 using an intuitive and powerful web interface. We have guides on installing pgAdmin 4 on other platforms.
Open source MVVM framework for ASP.NET Core and OWIN
View
@viewModel DotvvmDemo.CalculatorViewModel, Dotvvm
<p>
Enter the first number:
<dot:TextBox Text="{value: Number1}" />
</p>
<p>
Enter the second number:
<dot:TextBox Text="{value: Number2}" />
</p>
<p>
<dot:Button Text="Calculate" Click="{command: Calculate()}" />
</p>
<p>
The result is: {{value: Result}}
</p> ViewModel
using System;
namespace DotvvmDemo
{
public class CalculatorViewModel
{
public int Number1 { get; set; }
public int Number2 { get; set; }
public int Result { get; set; }
public void Calculate()
{
Result = Number1 + Number2;
}
}
}
This page describes how to use the Microsoft.CodeAnalysis.Metrics package to perform source code analysis of .NET assemblies from a console application. Visual Studio users can perform source code analysis by clicking the "Analyze" dropdown menu and selecting "Calculate Code Metrics", but I sought to automate this process so I can generate custom code analysis reports from console applications as part of my CI pipeline.
[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Login(LoginViewModel model, string returnUrl)
{
if (!ModelState.IsValid)
{
return View(model);
}
// This doesn't count login failures towards account lockout
// To enable password failures to trigger account lockout, change to shouldLockout: true
var result = await SignInManager.PasswordSignInAsync(model.Email, model.Password, model.RememberMe, shouldLockout: false);
switch (result)
{
case SignInStatus.Success:
return RedirectToLocal(returnUrl);
case SignInStatus.LockedOut:
return View("Lockout");
case SignInStatus.RequiresVerification:
return RedirectToAction("SendCode", new { ReturnUrl = returnUrl, RememberMe = model.RememberMe });
case SignInStatus.Failure:
default:
ModelState.AddModelError("", "Invalid login attempt.");
return View(model);
}
} var loggedinUser = await UserManager.FindAsync(model.Email, model.Password);
if (loggedinUser != null)
{
await UserManager.UpdateSecurityStampAsync(loggedinUser.Id);
} app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
LoginPath = new PathString("/Account/Login"),
Provider = new CookieAuthenticationProvider
{
// Enables the application to validate the security stamp when the user logs in.
// This is a security feature which is used when you change a password or add an external login to your account.
OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
validateInterval: TimeSpan.FromMinutes(30),
regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
}
}); OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>( TimeSpan.FromMinutes(0), // <-- Note the timer is set for zero (manager, user) => user.GenerateUserIdentityAsync(manager))
window.setInterval(function() {
$.ajax({
url:,
type: "Post",
dataType: "json",
success: function(data) {
if (!data) {
alert("Someone has logged in using your username and password!");
location.reload();
}
}
});
}, 60000); [AllowAnonymous]
public virtual ActionResult Authenticated()
{
return Json(User.Identity.IsAuthenticated);
} 
DECLARE
@search_string VARCHAR(100),
@table_name SYSNAME,
@table_id INT,
@column_name SYSNAME,
@sql_string VARCHAR(2000)
SET @search_string = 'display:none'
DECLARE tables_cur CURSOR FOR SELECT name, object_id FROM sys.objects WHERE type = 'U'
OPEN tables_cur
FETCH NEXT FROM tables_cur INTO @table_name, @table_id
WHILE (@@FETCH_STATUS = 0)
BEGIN
DECLARE columns_cur CURSOR FOR SELECT name FROM sys.columns WHERE object_id = @table_id AND system_type_id IN (167, 175, 231, 239)
OPEN columns_cur
FETCH NEXT FROM columns_cur INTO @column_name
WHILE (@@FETCH_STATUS = 0)
BEGIN
SET @sql_string = 'IF EXISTS (SELECT * FROM ' + @table_name + ' WHERE [' + @column_name + '] LIKE ''%' + @search_string + '%'') PRINT ''' + @table_name + ', ' + @column_name + ''''
EXECUTE(@sql_string)
FETCH NEXT FROM columns_cur INTO @column_name
END
CLOSE columns_cur
DEALLOCATE columns_cur
FETCH NEXT FROM tables_cur INTO @table_name, @table_id
END
CLOSE tables_cur
DEALLOCATE tables_cur Roles, Description Articles, Subject
DECLARE
@search_string VARCHAR(100),
@table_name SYSNAME,
@table_id INT,
@column_name SYSNAME,
@sql_string VARCHAR(2000)
SET @search_string = 'display:none' -- The spammy text to search for.
DECLARE tables_cur CURSOR FOR SELECT name, object_id FROM sys.objects WHERE type = 'U'
OPEN tables_cur
FETCH NEXT FROM tables_cur INTO @table_name, @table_id
WHILE (@@FETCH_STATUS = 0)
BEGIN
DECLARE columns_cur CURSOR FOR SELECT name FROM sys.columns WHERE object_id = @table_id AND system_type_id IN (167, 175, 231, 239)
OPEN columns_cur
FETCH NEXT FROM columns_cur INTO @column_name
WHILE (@@FETCH_STATUS = 0)
BEGIN
SET @sql_string = 'IF EXISTS (SELECT * FROM [' + @table_name + '] WHERE [' + @column_name + '] LIKE ''%' + @search_string + '%'') PRINT '' update [' + @table_name + '] set [' + @column_name + '] = substring([' + @column_name + '], 1, charindex(''''<'''', [' + @column_name + '])-1) where [' + @column_name + '] like ''''%<%'''''''
--PRINT @sql_string
EXECUTE(@sql_string)
FETCH NEXT FROM columns_cur INTO @column_name
END
CLOSE columns_cur
DEALLOCATE columns_cur
FETCH NEXT FROM tables_cur INTO @table_name, @table_id
END
CLOSE tables_cur
DEALLOCATE tables_cur update [Roles] set [Description] = substring([Description], 1, charindex('<', [Description])-1) where [Description] like '%<%'
update [Articles] set [Subject] = substring([Subject], 1, charindex('<', [Subject])-1) where [Subject] like '%<%' using System;
using System.Collections.Generic;
namespace EF_Sample02.Models
{
public class User
{
public int Id { set; get; }
public DateTime AddDate { set; get; }
public string Name { set; get; }
public string LastName { set; get; }
public string Email { set; get; }
public string Description { set; get; }
public byte[] Photo { set; get; }
public IList<Project> Projects { set; get; }
}
}
using System;
namespace EF_Sample02.Models
{
public class Project
{
public int Id { set; get; }
public DateTime AddDate { set; get; }
public string Title { set; get; }
public string Description { set; get; }
public virtual User User { set; get; }
}
}
using System;
using System.Collections.Generic;
using System.Data.Entity;
using EF_Sample02.Models;
namespace EF_Sample02
{
public class Sample2Context : DbContext
{
public DbSet<User> Users { set; get; }
public DbSet<Project> Projects { set; get; }
}
public class Sample2DbInitializer : DropCreateDatabaseAlways<Sample2Context>
{
protected override void Seed(Sample2Context context)
{
context.Users.Add(new User
{
AddDate = DateTime.Now,
Name = "Vahid",
LastName = "N.",
Email = "name@site.com",
Description = "-",
Projects = new List<Project>
{
new Project
{
Title = "Project 1",
AddDate = DateTime.Now.AddDays(-10),
Description = "..."
}
}
});
base.Seed(context);
}
}
}
<connectionStrings>
<add
name="Sample2Context"
connectionString="Data Source=(local);Initial Catalog=testdb2012;Integrated Security = true"
providerName="System.Data.SqlClient"
/>
</connectionStrings>
using System;
using System.Data.Entity;
namespace EF_Sample02
{
class Program
{
static void Main(string[] args)
{
Database.SetInitializer(new Sample2DbInitializer());
using (var db = new Sample2Context())
{
var project1 = db.Projects.Find(1);
Console.WriteLine(project1.Title);
}
}
}
}
CREATE TABLE [dbo].[Users](
[Id] [int] IDENTITY(1,1) NOT NULL,
[AddDate] [datetime] NOT NULL,
[Name] [nvarchar](max) NULL,
[LastName] [nvarchar](max) NULL,
[Email] [nvarchar](max) NULL,
[Description] [nvarchar](max) NULL,
[Photo] [varbinary](max) NULL,
CONSTRAINT [PK_Users] PRIMARY KEY CLUSTERED
(
[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
CREATE TABLE [dbo].[Projects](
[Id] [int] IDENTITY(1,1) NOT NULL,
[AddDate] [datetime] NOT NULL,
[Title] [nvarchar](max) NULL,
[Description] [nvarchar](max) NULL,
[User_Id] [int] NULL,
CONSTRAINT [PK_Projects] PRIMARY KEY CLUSTERED
(
[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[Projects] WITH CHECK ADD CONSTRAINT [FK_Projects_Users_User_Id] FOREIGN KEY([User_Id])
REFERENCES [dbo].[Users] ([Id])
GO
ALTER TABLE [dbo].[Projects] CHECK CONSTRAINT [FK_Projects_Users_User_Id]
GO
public class Project
{
[Key]
public int ThisIsMyPrimaryKey { set; get; }
[MaxLength(50, ErrorMessage = "حداکثر 50 حرف"), MinLength(4, ErrorMessage = "حداقل 4 حرف")]
public string Title { set; get; }
[Table("tblProject", Schema="guest")]
public class Project
[Column("DateStarted", Order = 4, TypeName = "date")]
public DateTime AddDate { set; get; }
[ConcurrencyCheck]
public string Name { set; get; }
[Timestamp]
public byte[] RowVersion { set; get; }
using System;
using System.Data.Entity;
namespace EF_Sample02
{
class Program
{
static void Main(string[] args)
{
Database.SetInitializer(new Sample2DbInitializer());
using (var db = new Sample2Context())
{
//update
var user = db.Users.Find(1);
user.Name = "User name 1";
db.SaveChanges();
}
}
}
}
exec sp_executesql N'update [dbo].[Users]
set [Name] = @0
where (([Id] = @1) and ([Name] = @2))
',N'@0 nvarchar(max) ,@1 int,@2 nvarchar(max) ',@0=N'User name 1',@1=1,@2=N'Vahid'
//delete
var user = db.Users.Find(1);
db.Users.Remove(user);
db.SaveChanges();
exec sp_executesql N'delete [dbo].[Users]
where (([Id] = @0) and ([Name] = @1))',N'@0 int,@1 nvarchar(max) ',@0=1,@1=N'Vahid'
exec sp_executesql N'delete [dbo].[Users]
where ((([Id] = @0) and ([Name] = @1)) and ([RowVersion] = @2))',N'@0 int,@1 nvarchar(max) ,
@2 binary(8)',@0=1,@1=N'Vahid',@2=0x00000000000007D1
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int Id { set; get; }
public enum DatabaseGeneratedOption
{
None = 0,
Identity = 1,
Computed = 2
}
[NotMapped]
public string FullName
{
get { return Name + " " + LastName; }
}
using System.ComponentModel.DataAnnotations;
namespace EF_Sample02.Models
{
[ComplexType]
public class InterestComponent
{
[MaxLength(450, ErrorMessage = "حداکثر 450 حرف")]
public string Interest1 { get; set; }
[MaxLength(450, ErrorMessage = "حداکثر 450 حرف")]
public string Interest2 { get; set; }
}
}
public InterestComponent Interests { set; get; }
CREATE TABLE [dbo].[Users](
---...
[Interests_Interest1] [nvarchar](450) NULL,
[Interests_Interest2] [nvarchar](450) NULL,
---...
namespace EF_Sample02.Models
{
public class User
{
public InterestComponent Interests { set; get; }
public User()
{
Interests = new InterestComponent();
}
}
}
[ForeignKey("FK_User_Id")]
public virtual User User { set; get; }
public int FK_User_Id { set; get; }
public class Book
{
public int ID {get; set;}
public string Title {get; set;}
[InverseProperty("Books")]
public Author Author {get; set;}
}
public class Author
{
public int ID {get; set;}
public string Name {get; set;}
[InverseProperty("Author")]
public virtual ICollection<Book> Books {get; set;}
}
public class Book
{
public int ID {get; set;}
public string Title {get; set;}
public Author FirstAuthor {get; set;}
public Author SecondAuthor {get; set;}
}
public class Author
{
public int ID {get; set;}
public string Name {get; set;}
public virtual ICollection<Book> BooksAsFirstAuthor {get; set;}
public virtual ICollection<Book> BooksAsSecondAuthor {get; set;}
}
public class Book
{
public int ID {get; set;}
public string Title {get; set;}
[InverseProperty("BooksAsFirstAuthor")]
public Author FirstAuthor {get; set;}
[InverseProperty("BooksAsSecondAuthor")]
public Author SecondAuthor {get; set;}
}
public class Author
{
public int ID {get; set;}
public string Name {get; set;}
[InverseProperty("FirstAuthor")]
public virtual ICollection<Book> BooksAsFirstAuthor {get; set;}
[InverseProperty("SecondAuthor")]
public virtual ICollection<Book> BooksAsSecondAuthor {get; set;}
}
using System.Collections.Generic;
namespace sample
{
public class MyList
{
public static List<int> GetListOfIntItems(int numberOfItems)
{
List<int> res = new List<int>();
for (int i = 0; i < numberOfItems; i++)
res.Add(i);
return res;
}
}
}
using NUnit.Framework;
using NUnit.Framework.SyntaxHelpers;
[TestFixture]
public class TestClass
[Test]
public void TestGetListOfIntItems()
[Test]
public void TestGetListOfIntItems()
{
const int count = 5;
List<int> items = sample.MyList.GetListOfIntItems(count);
Assert.That(items.Count,Is.EqualTo(5));
}
---------------------------
Assembly Not Loaded
---------------------------
System.ApplicationException : Unable to load TestLibrary because it is not located under
the AppBase
----> System.IO.FileNotFoundException : Could not load file or assembly
'TestLibrary' or one of its dependencies. The system cannot find the file specified.
For further information, use the Exception Details menu item.
# Use Pattern Matching to Avoid ‘As’ Followed by A ‘Null’ Check dotnet_diagnostic.IDE0019.severity = warning
You'll have to migrate to .NET 5 in the near future, and this article will help you prepare for this inevitable migration and avoid the last-minute, unexpected problems that will come up if you procrastinate.
