How to escape special characters when php accesses mysql data

How to escape special characters when PHP accesses mysql data: You can use the mysql library function to escape, the code is [mysql_escape_string(string $unescaped_string): string]. You can also use the escape function addslashes to escape.

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How to escape special characters when php accesses mysql data:

Method 1: Using mysql library functions

PHP version before 7.0:

mysql_escape_string ( string $unescaped_string ) : string

PHP version after 7.0:

mysqli_real_escape_string ( mysqli $link , string $escapestr ) : string

Method 2: Use the escape function addslashes()

Suitable for versions PHP4, PHP5, PHP7

addslashes ( string $str ) : string

Before PHP 5.4, the PHP command magic_quotes_gpc was on by default. In fact, all GET, POST and COOKIE data are used by addslashes(). Do not use addslashes() on strings that have been escaped by magic_quotes_gpc, as this will result in double escaping.

When encountering this situation, you can use the function get_magic_quotes_gpc() to detect it. That is, when get_magic_quotes_gpc() returns false, use addslashes() to escape special characters. Examples are as follows:

function myaddslashes($data)
{
    if(false == get_magic_quotes_gpc())
    {
        return addslashes($data);//未启用魔术引用时,转义特殊字符
    }
    return $data;
}

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