getNumCandle Problem

Settings= { 
            Name = "IndicatorName", 
            period = 5, 
            line = { 
                        { 
                        Name = "IndicatorMA", 
                        Color = RGB(0, 0, 255), 
                        Type = TYPE_LINE, 
                        Width = 2 
                        } 
                   }
          } 
          

function Init() 
    ---------------------------------------
    require "DelphianTransactor"
    internal.sqlConnect("sqlite-3","synDicator3.sqlite")
    ---------------------------------------
    MA_value=0
    
    return 1 
end 

function OnDestroy()
    internal.sqlDisconnect()
end

function get_bar(index)
    t={}
    n = getNumCandles (Settings.Name)
    t,_,_=getCandlesByIndex(Settings.Name,0,n-1,1)
    ltable=table.getn(t)
    message(tostring(ltable,1),1)
end

function OnCalculate(index) 
    if index < Settings.period then 
        return nil 
    else 
        local sum = 0 
        for i = index-Settings.period+1, index do
            sum = sum +C(i) 
        end 
        MA_value=sum/Settings.period
        get_bar(index)
        return MA_value
    end
end