对不起,但我不明白问题出在哪里。
这有效
$query_select_date = "SELECT * FROM 2013Currencies WHERE DateOfCurrencyRate = '2001-03-23'";
$sql_select_date = $db->prepare($query_select_date);
$sql_select_date->execute();
$data_select_date = $sql_select_date->fetchAll(PDO::FETCH_ASSOC);
但这不起作用(获取空数组)
$query_select_date = "SELECT * FROM 2013Currencies WHERE DateOfCurrencyRate = ?";
$cdate = "'2001-03-23'";// or $cdate = "2001-03-23"; or $cdate = 2001-03-23; result is the same
$sql_select_date->execute($cdate);
$data_select_date = $sql_select_date->fetchAll(PDO::FETCH_ASSOC);
我想有一些错误,但无法理解在哪里。