using System;
using System.Collections.Generic;
using Services.DataModels;
using System.Configuration;
using BLToolkit.Data;

namespace Main
{
    public class Dao
    {
        private string _connStr;
        public Dao(string connStr)
        {
            this._connStr = connStr;
        }
        public List<HRPostCriterionDataModel> GetAllData(int dateYear, int departId)
        {
            using (DbManager dbManager = new DbManager(_connStr))
            {
                return dbManager.SetSpCommand("GET_DATAFROM_POST_CRITERION",
                                              dbManager.Parameter("DATEYEAR", dateYear),
                                              dbManager.Parameter("DEPARTID", departId))
                    .ExecuteList<HRPostCriterionDataModel>();
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            string connStr = ConfigurationManager.ConnectionStrings["FbConnStr"].ConnectionString;
               Dao dao = new Dao(connStr);

            List <HRPostCriterionDataModel> lst = dao.GetAllData(40179, 12);
        }
    }
}

<?xml version="1.0" encoding="utf-8" ?>

<configuration>
  <connectionStrings>
    <add
         name             = "FbConnStr"
         connectionString = "character set=WIN1251;data source=LOCALHOST;Database=C:\Users\Grundick\Documents\Visual Studio 2010\Projects\Gsr.BusinessPlan\Скрипты\GSR.FDB;user id=SYSDBA;password=masterkey"
         providerName     = "FirebirdSql.Data.FirebirdClient" />
  </connectionStrings>

</configuration>

using (DbManager dbManager = new DbManager(_connStr))

using (DbManager dbManager = new DbManager("FbConnStr"))