C# Entity Framework: Keyword not supported: 'port'

The argument of the used base DbContext constructor is called nameOrConnectionString. Hence it supports a name of a connection string from the configuration file, or like in your case an actual connection string.

The problem with the later is that it doesn't allow specifying the provider name as with the former coming from the configuration, in which case EF uses the one specified in the defaultConnectionFactory configuration element, which in your case is System.Data.Entity.Infrastructure.SqlConnectionFactory, in other words - Sql Server, hence the port not supported exception.

There are several ways to fix the issue.

(A) Change the defaultConnectionFactory configuration:

<defaultConnectionFactory type="MySql.Data.Entity.MySqlConnectionFactory, MySql.Data.Entity.EF6"></defaultConnectionFactory>

(B) Use named configuration connection string and specify explicitly the provider:

<connectionStrings>
    <add name="MyDB" providerName="MySql.Data.MySqlClient" connectionString="server=myservername;port=3306;uid=myaccount;database=mydb;pwd=mypwd123" />
</connectionStrings>

and change the constructor to

public MyDB()
{
    // ...
}

or if the name is different than your DbContext derived class name:

public MyDB() : base(connection_string_name)
{
    // ...
}

(C) Use DbConfigurationTypeAttribute:

[DbConfigurationType(typeof(MySql.Data.Entity.MySqlEFConfiguration))]
public class MyDB : DbContext
{
    // ...
}

I had this problem whilst developing a Web Application on Core 2. I had to change the default database connection used from SqlServer to MySql in the Startup.cs file where the application is configured.

The error similar to the one listed above comes while working with ASP.net core and Database. The default database Provider with the ASP.net core is the SQL Server but, in case you are using a different provider for example, PostgreSQL and didn't correctly write or configure the DBContext code in the startup.cs

For example - Following code is written with an intent to connect to PostgresSQL then it will result in error ArgumentException: Keyword not supported: 'port'.

public void ConfigureServices(IServiceCollection services)
{
   services.AddMvc();
   var connection = @"Server=localhost;Port=5432;Database=NewDB;User Id=xxxxx;Password=cr@aaaa;";
   services.AddDbContext<BloggingContext>(options => options.UseSqlServer(connection));

    // ...

}

And the reasons is user is trying to connect to PostgreSQL but did change the default Option UseSQLServer after configuring the PostgreSQL string.

To fix the issue change the option

---

options.UseSqlServer(connection)) -> options.UseNpgsql(connection))

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