检查用户是否向表单添加了新图像 - check if user adds new image the form

check if user adds new image the form

我需要创建else动作。如果用户不上传新图像，数据库中应该保留旧图像。添加图像的代码是:

<?php 
require_once 'database.php';
require_once 'functions.php';
$content_pic = false;
$id = $_POST['id'];
$title = trim($_POST['title']);
$text = trim($_POST['text']);
if (!empty($_FILES["content_pic"])) {
        if ($_FILES["content_pic"]["error"] == UPLOAD_ERR_OK) {
            $uploads_dir = __DIR__ . '/files';
            $tmp_name = $_FILES["content_pic"]["tmp_name"];
            $name = $_FILES["content_pic"]["name"];
            if (move_uploaded_file($tmp_name, "{$uploads_dir}/{$name}")) {
                $content_pic = "files/{$name}";
            }
        }
    }else{    
    }    
$db = database_connect();
$stmt = $db->prepare($select_query);
$stmt->execute(array($id));
$result = $stmt->fetch(PDO::FETCH_ASSOC);    
$stmt = $db->prepare("UPDATE content SET title = ?, text= ?, content_pic = ? WHERE id = ? ");       
header("Location: item_view.php?id=" . $id);
exit();

我不知道如何创建else action

您可以尝试以下几行-其中变量$content_pic默认设置为false，因此如果没有上传图像，则可以执行不同的sql语句。

<?php
    if( isset( $_POST['id'], $_POST['title'], $_POST['text'] ) ){
        require_once 'database.php';
        require_once 'functions.php';

        $id     =   $_POST['id'];
        $title  =   trim( $_POST['title'] );
        $text   =   trim( $_POST['text'] );
        $field  =   'content_pic';

        /* will be populated if new upload detected */
        $content_pic = false;

        if( !empty( $_FILES[ $field ] ) ) {
            $file=$_FILES[ $field ];
            if( $file["error"] == UPLOAD_ERR_OK ) {
                $uploads_dir    = __DIR__ . '/files';
                $tmp_name       = $file['tmp_name'];
                $name           = $file['name'];
                $savepath       = $uploads_dir . DIRECTORY_SEPARATOR . $name;

                if( move_uploaded_file( $tmp_name, $savepath ) ) {
                    $content_pic = realpath( $savepath ) ? "files/{$name}" : false;
                }
            }
        }

        switch( $content_pic ){
            case false:
                $sql='update `content` set `title`=? `text`=? where `id`=?';
                $params=array( $title, $text, $id );
            break;
            default:
                $sql='update `content` set `title`=? `text`=?, `content_pic`=? where `id`=?';
                $params=array( $title, $text, $content_pic, $id );
            break;
        }
        $db = database_connect();
        $stmt = $db->prepare( $sql );
        $stmt->execute( $params );
        $db->close();
    }
?>