PHP MySQL：选择标题为年份的列

My table ('contas') has columns that correspond to years (2014, 2015, etc...) among other columns, like:

id   | name   | notes   |   2014   | 2015   | 2016
1    | abc    | whatever|   5.25   |  8.50  | 9.50

I want to use PHP to select the column that corresponds to the current year from that table.

I have:

$ano=date('Y');
$ano=(string)$ano;

$sql = "SELECT `id`, `name`, `notes`, $ano AS 'saldo' FROM `contas` WHERE ..."; 

$result = $pdo->query($sql);
$rows = $result->fetchAll(PDO::FETCH_ASSOC);

In the column 'saldo' I'm getting 2014 for every row, instead of the values of the table.

I tried inserting $ano into single and double quotes in the query, but it didn't work.

Escape the column name..

$sql = "SELECT `id`, `name`, `notes`, `$ano` AS 'saldo' FROM `contas` WHERE ...";

You could try this:

$ano=date('Y');

$sql = "SELECT `id`, `name`, `notes`,`".$ano."` AS 'saldo' FROM `contas` WHERE ...";