PHP SQL Server安全性方法-哪个更好？

如何解决PHP SQL Server安全性方法-哪个更好？

我正在学习PHP，并想问一下这两种不同方法中哪一种在sql Server安全性方面更好？假设它将用于登录表单。

功能＃1

function SanitizeInput($in,$len = 20)
    {
        return substr(preg_replace("/[^a-zA-Z0-9_]/","",htmlspecialchars(htmlentities(strip_tags($in)))),$len);
    }
    

用法：

$ username = $ thisDB-> SanitizeInput（$ _ POST ['username']）;

---

功能＃2＆3

    function security($text) {
    $text = trim($text);
    $search = array('','',',');
    $replace = array('C','c','G','g','i','I','O','o','S','s','U','u');
    $new_text = str_replace($search,$replace,$text);
    return $new_text;
}
function sqlSecurity($text) {
    $text = trim(htmlspecialchars($text));
    $search = array("'",'"',"TruncATE","truncate","UPDATE","update","SELECT","select","DROP","drop","DELETE","delete","WHERE","where","EXEC","exec","INSERT INTO","insert into","PROCEDURE","procedure","--");
    $replace = array("","");
    $new_text = str_replace($search,$text);
    return $new_text;
}

用法：

$ username = $ thisDB-> sqlSecurity（$ thisDB-> security（$ _ POST ['username']））;