ADO Database C#

using System;
using System.Data;
using System.Data.SqlClient;
class ExecuteDDL {
    public static void Main() {
        SqlConnection mySqlConnection = new SqlConnection("server=localhost;database=Northwind;uid=sa;pwd=sa");
        SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
        mySqlCommand.CommandText =
          "CREATE TABLE MyPersons (" +
          "  PersonID int CONSTRAINT PK_Persons PRIMARY KEY," +
          "  FirstName nvarchar(15) NOT NULL," +
          "  LastName nvarchar(15) NOT NULL," +
          "  DateOfBirth datetime" +
          ")";
        mySqlConnection.Open();
        Console.WriteLine("Creating MyPersons table");
        int result = mySqlCommand.ExecuteNonQuery();
        Console.WriteLine("mySqlCommand.ExecuteNonQuery() = " + result);
        mySqlCommand.CommandText =
          "ALTER TABLE MyPersons " +
          "ADD EmployerID nchar(5) CONSTRAINT FK_Persons_Customers " +
          "REFERENCES Customers(CustomerID)";
        result = mySqlCommand.ExecuteNonQuery();
        Console.WriteLine("mySqlCommand.ExecuteNonQuery() = " + result);
        mySqlCommand.CommandText = "DROP TABLE MyPersons";
        result = mySqlCommand.ExecuteNonQuery();
        Console.WriteLine("mySqlCommand.ExecuteNonQuery() = " + result);
        mySqlConnection.Close();
    }
}