Subject: Re: Problem about connect Postgre using ADO.NET
To: NGUYEN TRONG LANH <t_lanh@brycen.com.vn>, pgsql-docs@postgresql.org
References: <cef19a6a-5835-403a-9e32-024ce40986f5@brycen.com.vn>
Newsgroups: gmane.comp.db.postgresql.devel.documentation
From: Neil Anderson <neil@postgrescompare.com>
Organization: Postgres Compare
Message-ID: <cba2fdd6-b0bf-a19d-e95d-264ec4d9d58e@postgrescompare.com>
Date: Sat, 10 Jun 2017 19:20:08 -0400
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On 2017-05-23 3:17 AM, NGUYEN TRONG LANH wrote:
> Hello pgsql support team!
>
> At first, forgive me if the content of the email is not your
> responsibility. I have problem when I try connect Postgre using ADO.NET,
> I not see PostgreSQL in Data Source list.
>
> I have done to install Npgsql package, install Npgsql PostgreSQL
> extension but the problem is not solve.

Hi, I use Npgsql in my project. I'm not sure what you mean by 'I do not 
see PostgreSQL in Data Source list', Npgsql does not discover the server 
for you, you must provide it with a connection string, create a 
connection and execute commands. Here is a code example:

var connString = 
"Host=localhost;Username=postgres;Password=passwrd;Database=postgres";

using (var conn = new NpgsqlConnection(connString))
{
     conn.Open();

     // Insert some data
     using (var cmd = new NpgsqlCommand())
     {
         cmd.Connection = conn;
         cmd.CommandText = "INSERT INTO data (some_field) VALUES (@p)";
         cmd.Parameters.AddWithValue("p", "Hello world");
         cmd.ExecuteNonQuery();
     }

     // Retrieve all rows
     using (var cmd = new NpgsqlCommand("SELECT some_field FROM data", 
conn))
     using (var reader = cmd.ExecuteReader())
         while (reader.Read())
             Console.WriteLine(reader.GetString(0));
}

For future reference Npgsql have wonderful documentation here 
http://www.npgsql.org/index.html, and they prefer questions be posted to 
Stack Overflow.

-- 
Neil Anderson
neil@postgrescompare.com
http://blog.postgrescompare.com


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