How to connect NpgsqlDatabaseInfo for crate database in C#

CrateDB
7

thank you for the reply…
My problem is connection with crate db. just leave the other part.
Now i remove the RegisterFactory and using Npgsql;

Then i got an error

> Npgsql.NpgsqlException (0x80004005): Exception while reading from stream
>  ---> System.TimeoutException: Timeout during reading attempt
>    at Npgsql.NpgsqlReadBuffer.<Ensure>g__EnsureLong|40_0(NpgsqlReadBuffer buffer, Int32 count, Boolean async, Boolean readingNotifications)
>    at Npgsql.NpgsqlConnector.RawOpen(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
>    at Npgsql.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
>    at Npgsql.ConnectorPool.OpenNewConnector(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
>    at Npgsql.ConnectorPool.<>c__DisplayClass38_0.<<Rent>g__RentAsync|0>d.MoveNext()
> --- End of stack trace from previous location where exception was thrown ---
>    at Npgsql.NpgsqlConnection.<>c__DisplayClass41_0.<<Open>g__OpenAsync|0>d.MoveNext()
> --- End of stack trace from previous location where exception was thrown ---
>    at Npgsql.NpgsqlConnection.Open()
at Implementation/crateRepository.cs:line 15

My code is

using System;
using Npgsql;

namespace test
{
    class Program
    {
        static void Main(string[] args)
        {
            string connString = "Host=localhost;Username=crate;SSL Mode=Prefer;Database=doc";

            using (var conn = new NpgsqlConnection(connString))

            {
                conn.Open();

                var tableName = "testtable";
                var cmd = $"select timestamp as unixtime,reading from {tableName} where id=@s AND timestamp>=@st AND timestamp<=@et ORDER BY unixtime ASC";

                using (NpgsqlCommand sqlCmd = new NpgsqlCommand(cmd, conn))
                {
                    sqlCmd.Parameters.AddWithValue("s", "a");
                    sqlCmd.Parameters.AddWithValue("st", 1622716474405);
                    sqlCmd.Parameters.AddWithValue("et", 1622716474837);

                    using (var reader = sqlCmd.ExecuteReader())
                    {
                        while (reader.HasRows && reader.Read())
                        {
                            Console.WriteLine(reader["unixtime"]);
                        }
                    }
                }
            }
        }
    }

}

The error is:

error at                 conn.Open();