using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var sql = GetAddToArrayQuery("person", "permissions", "id");

        Console.WriteLine(sql);

    }

        public static string GetAddToArrayQuery(string tablename, string arrayFieldName, params string[] keys)

        {

            var keyfieldnames = string.Join(',', keys);

            var keyvaluenames = string.Join(',', keys.Select(x => "@" + x));

​

            return $"" +

                $"INSERT INTO ${tablename}({keyfieldnames},{arrayFieldName}) " +

                $"VALUES({keyfieldnames},@{arrayFieldName}) " +

                $"ON CONFLICT({keyfieldnames}) DO UPDATE " +

                $"SET {arrayFieldName} = array(select distinct v from unnest({tablename}.{arrayFieldName} || @{arrayFieldName}) v";

        }

}