$username=addslashes($username);
mysql_escape_string($string)：用反斜杠转义字符串中的分外字符，用于mysql_query()查询。
$username=mysql_escape_string($username);
mysql_real_escape_string($string)：转义SQL语句中利用的字符串中的分外字符，并考虑到连接确当前字符集，须要担保当前是连接状态才能用该函数，否则会报警告。 不转义%与_
$username=mysql_real_escape_string($username);
两种选择：利用PDO
$stmt = $pdo->prepare('SELECT FROM user WHERE name = :name');
$stmt->execute(array(':name' => $name));
foreach ($stmt as $row) {
// do something with $row
}
利用mysqli
$stmt = $dbConnection->prepare('SELECT FROM user WHERE name = ?');
$stmt->bind_param('s', $name);
$stmt->execute();
$result = $stmt->get_result();
while ($row = $result->fetch_assoc()) {
// do something with $row
}
