PHP code to prevent sql injection

/***************************
Description:
Determine whether the passed variable contains illegal characters
such as $_POST, $_GET
Function: Anti-injection
* *************************/
//Illegal characters to be filtered
$ArrFiltrate=array("'", ";","union");
//The url to jump to after an error occurs. If not filled in, the previous page will be defaulted
$StrGoUrl="";
//Whether there is a value in the array
function FunStringExist($StrFiltrate, $ArrFiltrate){
foreach ($ArrFiltrate as $key=>$value){
if (eregi($value,$StrFiltrate)){
return true;
}
}
return false;
}
//Merge $_POST and $_GET
if(function_exists(array_merge)){
$ArrPostAndGet=array_merge($HTTP_POST_VARS,$HTTP_GET_VARS);
}else{
foreach($HTTP_POST_VARS as $key=> ;$value){
$ArrPostAndGet[]=$value;
}
foreach($HTTP_GET_VARS as $key=>$value){
$ArrPostAndGet[]=$value;
}
}
 //Verification starts
foreach($ArrPostAndGet as $key=>$value){
if (FunStringExist($value,$ArrFiltrate)){
echo "";
if (emptyempty($StrGoUrl)){
echo " ";
}else{
echo "";
}
exit;
}
}
? >

and save it as checkpostandget.php, and then add include("checkpostandget.php"); in front of each php file.

Method 2

/* Filter all GET variables*/
foreach ($_GET as $get_key=>$get_var)
{
if (is_numeric($get_var)) {
$get[strtolower($get_key)] = get_int($get_var);
} else {
$get[strtolower($get_key)] = get_str($get_var);
}
}
< ;p>/* Filter all POST variables*/
foreach ($_POST as $post_key=>$post_var)
{
if (is_numeric($post_var)) {
$post[strtolower($post_key)] = get_int($post_var);
} else {
$post[strtolower($post_key)] = get_str($post_var);
}
}
/* Filter function*/
// Integer filter function
function get_int($number)
{
return intval($number);
}
//String filter function
function get_str($string)
{
if (!get_magic_quotes_gpc()) {
 return addslashes($string);
}
return $string;
}
?>