Simple method to implement SQL injection prevention in php_php skills

The example in this article describes how to simply implement SQL injection prevention in PHP. Share it with everyone for your reference, the details are as follows:

There is not much filtering here, mainly for the combination of php and mysql.

For general injection prevention, just use PHP’s addslashes function.

The following is a copied code:

PHP code:

$_POST = sql_injection($_POST);
$_GET = sql_injection($_GET);
function sql_injection($content)
{
if (!get_magic_quotes_gpc()) {
if (is_array($content)) {
foreach ($content as $key=>$value) {
$content[$key] = addslashes($value);
}
} else {
addslashes($content);
}
}
return $content;
}

If you want to build a system, you can use the following code, which is also copied.

PHP code:

function inject_check($sql_str) {
 return eregi('select|insert|update|delete|\'|\/\*|\*|\.\.\/|\.\/|union|into|load_file|outfile', $sql_str);  // 进行过滤
}
function verify_id($id=null) {
 if (!$id) { exit('没有提交参数！'); }  // 是否为空判断
 elseif (inject_check($id)) { exit('提交的参数非法！'); }  // 注射判断
 elseif (!is_numeric($id)) { exit('提交的参数非法！'); }  // 数字判断
 $id = intval($id);  // 整型化
 return $id;
}
function str_check( $str ) {
 if (!get_magic_quotes_gpc()) {  // 判断magic_quotes_gpc是否打开
  $str = addslashes($str);  // 进行过滤
 }
 $str = str_replace("_", "\_", $str);  // 把 '_'过滤掉
 $str = str_replace("%", "\%", $str);  // 把 '%'过滤掉
 return $str;
}
function post_check($post) {
 if (!get_magic_quotes_gpc()) {  // 判断magic_quotes_gpc是否为打开
  $post = addslashes($post);  // 进行magic_quotes_gpc没有打开的情况对提交数据的过滤
 }
 $post = str_replace("_", "\_", $post);  // 把 '_'过滤掉
 $post = str_replace("%", "\%", $post);  // 把 '%'过滤掉
 $post = nl2br($post);  // 回车转换
 $post = htmlspecialchars($post);  // html标记转换
 return $post;
}

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I hope this article will be helpful to everyone in PHP programming.