BL.Empleados.GetPositionId C# (CSharp) Method

        public int GetPositionId(string nombrecargo)
        {
            try
               {
                   var query = from pos in entities.cargos
                               where nombrecargo == pos.cargo1
                               select pos.id;
                   int posId = Convert.ToInt32(query.First());

                   return posId;
               }catch(Exception err){
                   throw new Exception(err.ToString() + "--Empleados.cs / GetPositionId(string)");
               }
        }