如何使用php pdo以逗号分隔在一行中上传多个图像并显示它们

I want to upload multiple image using PDO in one row with comma separation, however I can only able to insert one image to database but in the upload directory all selected files are moved. How to do it?

<?php
for($x=0; $x<count($_FILES['pic']['tmp_name']); $x++ ) {
$file_name = $_FILES['pic']['name'][$x];
$file_size = $_FILES['pic']['size'][$x];
$file_tmp = $_FILES['pic']['tmp_name'][$x];
$t = explode(".", $file_name);
$t1 = end($t);
$file_ext = strtolower(end($t));
$ext_boleh = array("jpg", "jpeg", "png", "gif", "bmp"); 
if(in_array($file_ext, $ext_boleh)) {
$dir = 'uploads/';
$sumber = $file_tmp; 
move_uploaded_file($sumber, $dir.$file_name);
$sql2 = "UPDATE project_detail SET pic = :pic WHERE no = '$no'"; 
$statement1 = $connection->prepare($sql2);
if ($statement1->execute([':pic' => $file_name])){ ?> 
<script> 
alert("new record uploded successfully"); 
window.location.href=('project.php'); 
</script>
<?php }
}else {
echo "Only Images can be store!";
}
}
?>

If I've understood correctly ( though I'm still confused by the update satement rather than an insert statement ) then a little re-writing to perform all the upload actions before trying to write to the db should work.

<?php

    $images=[];

    for( $x=0; $x < count( $_FILES['pic']['tmp_name'] ); $x++ ) {


        $file_name = $_FILES['pic']['name'][$x];
        $file_size = $_FILES['pic']['size'][$x];
        $file_tmp = $_FILES['pic']['tmp_name'][$x];

        /* Less complicated and more reliable method to find the file extension!! */
        $file_ext = strtolower( pathinfo( $file_name, PATHINFO_EXTENSION ) );
        $ext_boleh = array( 'jpg', 'jpeg', 'png', 'gif', 'bmp' );

        if( in_array( $file_ext, $ext_boleh ) ) {

            $dir = 'uploads/';

            $status = move_uploaded_file( $file_tmp, $dir . $file_name );
            /* 
                if the file was moved OK then add it's name 
                to the images array - this will be used in 
                the sql later...
            */
            if( $status )$images[]=$file_name;

        }
    }

    /* 
        Where does `$no` come from? 

        Construct update ( or insert? ) sql statement
        making sure we do not leave potential injection
        possibilities....!
    */
    $sql2 = 'UPDATE `project_detail` SET `pic` = :pic WHERE `no` = :no';
    $statement1 = $connection->prepare( $sql2 );

    /* Concatenate the image names into a comma separated string */
    $args = array(
        ':pic'  =>  implode(',', $images ),
        ':no'   =>  $no
    );
    $result = $statement1->execute( $args );

    if( $result ){
        /* do a happy dance */
    } else {
        /* weep */
    }
?>