使用花括号动态选择列

Question

I am trying to select a column with curly braces, but the column has a prefix, for example:

    //sql to run
    $sql = "SELECT * FROM trades 
            WHERE trade_market = ? 
            AND trade_buysell = ?
            " . $order . "";

    //run the sql
    $tickersHigh = $database->prepare($sql);
    $tickersHigh->execute(array(strtolower($market), $buysell));

    //fetch the results
    $tickerHigh = $tickersHigh->fetch();

    //return the results
    return $tickerHigh->trade_{$type};

Since I have added trade_ to my column name it no longer works, it used to work like so:

return $tickerHigh->{$type};

But I recently added the prefix trade_ to my columns, like so:

 return $tickerHigh->trade_{$type};

And I get the error:

Column not found: 1054 Unknown column 'PRICE' in 'order clause'

It should be selecting trade_price rather than just price

so how can I get this to work with my prefix too?

My table:

CREATE TABLE `trades` (
  `trade_id` int(11) NOT NULL,
  `trade_amount` text NOT NULL,
  `trade_market` varchar(25) NOT NULL,
  `trade_cost` varchar(25) NOT NULL,
  `trade_fee` varchar(25) NOT NULL,
  `trade_time` time NOT NULL,
  `trade_user` varchar(25) NOT NULL,
  `trade_ip` varchar(25) NOT NULL,
  `trade_price` text NOT NULL,
  `trade_buysell` text NOT NULL,
  `trade_date` datetime NOT NULL,
  `trade_maincoin` text NOT NULL,
  `trade_charttime` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

Answer 1

try

return $tickerHigh->{"trade_$type"};