Postgresql - Create Database & Table dynamically

Solution:

    // 1. Connect to server to create database:
    const string connStr = "Server=localhost;Port=5432;User Id=postgres;Password=enter;";

    // 2. Connect to server to create table:
    const string connStr2 = "Server=localhost;Port=5432;User Id=postgres;Password=enter;Database=testDb";


    var m_conn = new NpgsqlConnection(connStr); // db connction
    var m_conn2 = new NpgsqlConnection(connStr2); // table connection

    // creating a database in Postgresql
    m_createdb_cmd = new NpgsqlCommand("CREATE DATABASE IF NOT EXISTS  \"testDb\" " +
                                   "WITH OWNER = \"postgres\" " +
                                   "ENCODING = 'UTF8' " +
                                   "CONNECTION LIMIT = -1;", m_conn);

    // creating a table in Postgresql
    m_createtbl_cmd = new NpgsqlCommand
       {
       CommandText ="CREATE TABLE table1(ID CHAR(256) CONSTRAINT id PRIMARY KEY, Title CHAR)"
       };

       m_createtbl_cmd.Connection = m_conn2;

 // 3.. Make connection and create

        // open connection to create DB
        m_conn.Open();
        m_createdb_cmd.ExecuteNonQuery();
        m_conn.Close();

        // open connection to create table
        m_conn2.Open();
        m_createtbl_cmd.ExecuteNonQuery();
        m_conn2.Close();

This works but is there a shorter way to do this? I had to create two Npgsql connections. I don't know, just doesn't look very elegant to me.

I would do this:

string connStr = "Server=localhost;Port=5432;User Id=postgres;Password=enter;";
var m_conn = new NpgsqlConnection(connStr);
var m_createdb_cmd = new NpgsqlCommand(@"
    CREATE DATABASE IF NOT EXISTS testDb
    WITH OWNER = postgres
    ENCODING = 'UTF8'
    CONNECTION LIMIT = -1;
    ", m_conn);
m_conn.Open();
m_createdb_cmd.ExecuteNonQuery();
m_conn.Close();

connStr = "Server=localhost;Port=5432;User Id=postgres;Password=enter;Database=testDb";
m_conn = new NpgsqlConnection(connStr);
m_createtbl_cmd = new NpgsqlCommand(
   "CREATE TABLE table1(ID CHAR(256) CONSTRAINT id PRIMARY KEY, Title CHAR)"
   , m_conn);
m_conn.Open();
m_createtbl_cmd.ExecuteNonQuery();
m_conn.Close();

The use of var here is not recommended. I used it as I don't know what are the returned types but you should.

Notice the use of a raw string (@). It makes string building simple.

Do not use identifiers surrounded by double quotes in Postgresql unless the identifier is otherwise illegal. It will make you life much harder.