Lua MySQL Delete Results Os.time() > result

[beenii]

executed:

SELECT `player_id`,`pid`,`sid`,CONVERT(`attributes` USING latin1 ) FROM `player_items` WHERE CONVERT(`attributes` USING latin1 ) LIKE '%timerOnExp%'

and have this results

how delete in lua for tfs 1.2
if timerOnExp < os.time() ?

i try

local TItoDelete = db.storeQuery("SELECT `player_id`,`pid`,`sid`,CONVERT(`attributes` USING latin1 ) AS `attr` FROM `player_items` WHERE CONVERT(`attributes` USING latin1 ) LIKE '%timerOnExp%'")

    if TItoDelete then -- if the MySQL result is not empty
        repeat
            local attrstring = result.getString(TItoDelete, "attr") -- get the attribute
            local attrnumber = tonumber(string.sub(attrstring, -12, string.len(attrstring)-2)) -- here I try to get only the number (I'm not sure if it will work)
            if (os.time() >= attrnumber) then
        local playerid = result.getNumber(TItoDelete, "player_id")
        local pid      = result.getNumber(TItoDelete, "pid")
                local sid      = result.getNumber(TItoDelete, "sid")
                db.storeQuery("DELETE FROM `player_items` WHERE `player_id`="..playerid.." AND `pid` = "..pid.." AND `sid` ="..sid) -- deletes item
               end
        until not result.next(TItoDelete)
    end

but dont work

bad argument #1 to 'len' <string expected, got boolean)