Analysis of PHP batch deletion method

You can refer to the following articlehttps:///article/
SQL：$SQL="delete from `doing` where id in ('1,2,3,4')";
Data are separated by commas.
Form:

Copy the codeThe code is as follows:

<form action="?action=doing" method="post"> 
<input name="ID_Dele[]" type="checkbox"  value="1"/> 
<input name="ID_Dele[]" type="checkbox"  value="2"/> 
<input name="ID_Dele[]" type="checkbox"  value="3"/> 
<input name="ID_Dele[]" type="checkbox"  value="4"/> 
<input type="submit"/> 
</form> 

OK $ID_Dele=$_POST['ID_Dele'] will be an array. Although PHP is of weak type, there is no weak ASP here.
ASP can:
SQL="delete from [doing] where id in ('"&ID_Dele&"')" to delete. But PHP cannot put $ID_Dele directly in. Because $ID_Dele is not '1,2,3,4', because $ID_Dele is an array with keys and values.
OK, it's not difficult in PHP. There is a function: implode(), right. A function that is exactly the opposite of split() exploit() function, the latter two are divided by a certain character (such as a comma), while the former can be spliced into a string.
therefore:

Copy the codeThe code is as follows:

 
$ID_Dele= implode(",",$_POST['ID_Dele']); 
$SQL="delete from `doing` where id in ($ID_Dele)"; 

I provide the test code:

Copy the codeThe code is as follows:

<meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> 
<?php 
if ($_POST["action"]="doing"){ 
$del_id=$_POST["ID_Dele"]; 
$ID_Dele= implode(",",$_POST['ID_Dele']); 
echo "After merge:".$ID_Dele."<br />Before merge:";
if($del_id!=""){ 
$del_num=count($del_id); 
for($i=0;$i<$del_num;$i++){ 
echo $del_id[$i]; 
} 
} 
}else{ 
echo "Please submit";
} 

?> 
<form action="?action=doing" method="post"> 
<input name="ID_Dele[]" type="checkbox" value="1st"/>1st
<input name="ID_Dele[]" type="checkbox" value="2nd"/>2nd
<input name="ID_Dele[]" type="checkbox" value="3rd"/>3rd
<input name="ID_Dele[]" type="checkbox" value="4th"/>4th
<input type="submit"/> 
</form> 