我有一个可以上传和删除照片的应用。现在我要么能够上传照片，要么我能够删除它。但出于某种原因，我无法做到这两点，这就是我的意思：
在下面的代码中，在Photograph类中，变量$ db_fields是照片数据库中列的数组。如果我将id字段从$ db_fields数组中删除，我可以上传照片。但我无法删除照片。如果我包含id字段，我可以删除照片，但现在我无法上传照片。
我需要在这做什么？如果您需要查看其他任何内容，请告诉我们。
谢谢， CM
photograph.php
<?php
require_once(LIB_PATH . DS . 'database.php');
class Photograph extends DatabaseObject {
protected static $table_name = "photographs";
protected static $db_fields = array('id','filename', 'type', 'size', 'caption');
public $id;
public $filename;
public $type;
public $size;
public $caption;
private $temp_path;
protected $upload_dir = "images";
public $errors = array();
protected $upload_errors = array(
UPLOAD_ERR_OK => "No errors.",
UPLOAD_ERR_INI_SIZE => "Larger than upload_max_filesize.",
UPLOAD_ERR_FORM_SIZE => "Larger than form MAX_FILE_SIZE.",
UPLOAD_ERR_PARTIAL => "Partial upload.",
UPLOAD_ERR_NO_FILE => "No file.",
UPLOAD_ERR_NO_TMP_DIR => "No temporary directory.",
UPLOAD_ERR_CANT_WRITE => "Can't write to disk.",
UPLOAD_ERR_EXTENSION => "File upload stopped by extension."
);
public function attach_file($file) {
if (!$file || empty($file) || !is_array($file)) {
$this->errors[] = "No file was uploaded.";
return false;
} elseif ($file['error'] != 0) {
$this->errors[] = $this->upload_errors[$file['error']];
return false;
} else {
$this->temp_path = $file['tmp_name'];
$this->filename = basename($file['name']);
$this->type = $file['type'];
$this->size = $file['size'];
return true;
}
}
public function save() {
if (isset($this->id)) {
$this->update();
} else {
if (!empty($this->errors)) {
return false;
}
if (strlen($this->caption) > 255) {
$this->errors[] = "The caption can only be 255 characters long.";
return false;
}
if (empty($this->filename) || empty($this->temp_path)) {
$this->errors[] = "The file location was not available.";
return false;
}
$target_path = SITE_ROOT . DS . 'public' . DS . $this->upload_dir . DS . $this->filename;
if (file_exists($target_path)) {
$this->errors[] = "The file {$this->filename} already exists.";
return false;
}
if (move_uploaded_file($this->temp_path, $target_path)) {
if ($this->create()) {
unset($this->temp_path);
return true;
}
} else {
$this->errors[] = "The file upload failed, possibly due to incorrect permissions on the upload folder.";
return false;
}
}
}
public function destroy() {
if ($this->delete()) {
$target_path = SITE_ROOT . DS . 'public' . DS . $this->image_path();
return unlink($target_path) ? true : false;
} else {
return false;
}
}
public function image_path() {
return $this->upload_dir . DS . $this->filename;
}
public function size_as_text() {
if ($this->size < 1024) {
return "{$this->size} bytes";
} elseif ($this->size < 1048576) {
$size_kb = round($this->size / 1024);
return "{$size_kb} KB";
} else {
$size_mb = round($this->size / 1048576, 1);
return "{$size_mb} MB";
}
}
public function comments() {
return Comment::find_comments_on($this->id);
}
public static function count_all() {
global $database;
$sql = "SELECT COUNT(*) FROM ".self::$table_name;
$result_set = $database->query($sql);
$row = $database->fetch_array($result_set);
return array_shift($row);
}
}
?>
database_object.php
require_once(LIB_PATH . DS . 'database.php');
class DatabaseObject {
private static $table_name;
public static function find_all() {
global $database;
$query = "SELECT * FROM ".static::$table_name;
return static::find_by_sql($query);
}
public static function find_by_id($id=0) {
global $database;
$query = "SELECT * FROM " . static::$table_name . " WHERE id =".$database->escape_value($id)." LIMIT 1";
$result_array = static::find_by_sql($query);
return !empty($result_array) ? array_shift($result_array) : false;
}
public static function find_by_sql($sql = "") {
global $database;
$result_set = $database->query($sql);
$object_array = array();
while ($row = $database->fetch_array($result_set)) {
$object_array[] = static::instantiate($row);
}
return $object_array;
}
private static function instantiate($record) {
$object = new static();
foreach ($record as $attribute => $value) {
if ($object->has_attribute($attribute)) {
$object->$attribute = $value;
}
}
return $object;
}
private function has_attribute($attribute) {
$object_vars = $this->attributes();
return array_key_exists($attribute, $object_vars);
}
protected function attributes() {
$attributes = array();
foreach (static::$db_fields as $field) {
if (property_exists($this, $field)) {
$attributes[$field] = $this->$field;
}
}
return $attributes;
}
protected function sanitized_attributes() {
global $database;
$clean_attributes = array();
foreach ($this->attributes() as $key => $value) {
$clean_attributes[$key] = $database->escape_value($value);
}
return $clean_attributes;
}
public function save() {
return isset($this->id) ? $this->update() : $this->create();
}
public function create() {
global $database;
$attributes = $this->attributes();
$sql = "INSERT INTO ".static::$table_name." (";
$sql .= join(", ", array_keys($attributes));
$sql .= ") VALUES ('";
$sql .= join("', '", array_values($attributes));
$sql .= "')";
if($database->query($sql)) {
$this->id = $database->insert_id();
return true;
} else {
return false;
}
}
public function update() {
global $database;
$attributes = $this->sanitized_attributes();
$attribute_pairs = array();
foreach ($attributes as $key => $value) {
$attribute_pairs[] = "{$key}='{$value}'";
}
$sql = "UPDATE " . static::$table_name . " SET ";
$sql .= join(", ", $attribute_pairs);
$sql .= " WHERE id=" . $database->escape_value($this->id);
$database->query($sql);
return ($database->affected_rows() == 1) ? true : false;
}
public function delete() {
global $database;
$sql = "DELETE FROM " . static::$table_name;
$sql .= " WHERE id=" . $database->escape_value($this->id);
$sql .= " LIMIT 1";
$database->query($sql);
return ($database->affected_rows() == 1) ? true : false;
}
}
?>
photo_upload.php
<?php
require_once('../../includes/initialize.php');
if (!$session->is_logged_in()) {
redirect_to("login.php");
}
?>
<?php
$max_file_size = 10485760; // expressed in bytes
// 10240 = 10 KB
// 102400 = 100 KB
// 1048576 = 1 MB
// 10485760 = 10 MB
//2e+6
$message="";
if (isset($_POST['submit'])) {
$photo = new Photograph();
$photo->caption = $_POST['caption'];
$photo->attach_file($_FILES['file_upload']);
if ($photo->save()) {
// Success
$session->message("Photograph uploaded successfully.");
redirect_to('list_photos.php');
} else {
// Failure
$message = join("<br />", $photo->errors);
}
}
?>
<?php include_layout_template('admin_header.php'); ?>
<h2>Photo Upload</h2>
<?php echo output_message($message); ?>
<form action="photo_upload.php" enctype="multipart/form-data" method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="<?php echo $max_file_size; ?>" />
<p><input type="file" name="file_upload" /></p>
<p style="font-color:#000;">Caption: <input type="text" name="caption" value="" /></p>
<input type="submit" name="submit" value="Upload" />
</form>
<?php include_layout_template('admin_footer.php'); ?>
来自＆＃39; database_object.php＆＃39;
public function create() {
global $database;
$attributes = $this->attributes();
$sql = "INSERT INTO ".static::$table_name." (";
$sql .= join(", ", array_keys($attributes));
$sql .= ") VALUES ('";
$sql .= join("', '", array_values($attributes));
$sql .= "')";
if($database->query($sql)) {
$this->id = $database->insert_id();
return true;
} else {
return false;
}
}
答案 0 :(得分：0)
临时解决方案的摘要，因此您可以完成此问题。
在create的方法中，您将使用$attributes = $this->attributes();获取所有属性（字段），然后使用数组键和值生成SQL语句。
这还包括id字段。
然后问题是尝试执行INSERT操作并包含id字段（它似乎是auto_increment唯一索引字段）。这对创建造成了很大的问题。
一个临时解决方案是，在$attributes完成此操作之后使用unset($attributes['id']);从您用于构建查询的$attributes = $this->attributes();中删除该字段，但它不漂亮且可以开发以后在闲暇时更好。
我希望我能帮助，并且快乐编码;）