代码之家 › 专栏 › 技术社区 › kold-kreator

在singleton中有两个关于php crud的实例

crud instance php

kold-kreator · 技术社区 · 8 年前

这是我的CRUD文件和连接文件。

$pdo        = Connection::getInstance();
$crud       = Crud::getInstance($pdo);
# ----------------------------------------
$sql        = "SELECT * FROM images WHERE prod_id = ?";
$arrayParam = array($prod_id);
$data_img   = $crud->getSQLGeneric($sql, $arrayParam, true);

$pdo        = Connection::getInstance();
$crud       = Crud::getInstance($pdo,'images');
# ----------------------------------------
$arrayImg   = array('img_id=' => $img_id);
$return     = $crud->delete($arrayImg);

我不能同时执行这两个语句。假设我需要在同一个代码块中进行插入和删除,它只运行其中的一个。

$prod_id    = $_GET['prod'];
# -----
$pdo        = Connection::getInstance();
# ----------------------------------------
$crud       = Crud::getInstance($pdo);
# -----
$sql        = "SELECT * FROM images WHERE prod_id = ?";
$arrayParam = array($prod_id);
$data_img   = $crud->getSQLGeneric($sql, $arrayParam, true);
# -----
foreach($data_img as $img_info)
{
  unlink('../../img/'.$img_info->img_name);
  $arrayImg = array('img_id=' => $img_info->img_id);
  $return2  = $crud->delete($arrayImg);
}
# ----------------------------------------
$crud       = Crud::getInstance($pdo,'products');
# -----
$arrayDel   = array('prod_id=' => $prod_id);
$return     = $crud->delete($arrayDel);
# ----------------------------------------
echo 'Deleted';

欢迎任何帮助!

2 回复 | 直到 8 年前

Yanis-git 8 年前

我建议你用这个来修改你的单例逻辑。

class Crud
{
    private $pdo         = null; # Storing PDO connection
    private $table       = null; # Storing table name
    private static $crud = []; # Static attribute that contains a self instance

  # ----------------------------------------
    # Class constructor -> PUBLIC method
    # ----------------------------------------
    public function __construct($connection, $table = 'default')
    {
        if (!empty($connection)) {
            $this->pdo = $connection;
        } else {
            echo 'ConexÃ£o inexistente!';
            exit();
        }

        if (!empty($table) && $table !== 'default') {
            $this->table =$table;
        }
    }

    # ----------------------------------------
    # Static public method that returns a Crud class instance
    # ----------------------------------------
    public static function getInstance($connection, $table = 'default')
    {
        # Verifying if there's a class instance
        if (!isset(self::$crud[$table])) {
            try {
                self::$crud[$table] = new Crud($connection, $table);
            } catch (Exception $e) {
                echo 'Error '.$e->getMessage();
            }
        }
        return self::$crud[$table];
    }
}

$crud 作为数组,并按表名隔离存储每个实例。

        if (!isset(self::$crud[$table])) {
            try {
                self::$crud[$table] = new Crud($connection, $table);
            } catch (Exception $e) {
                echo 'Error '.$e->getMessage();
            }
        }

因此,以下代码的工作方式如下:

Crud::getInstance($pdo); // Create new instance and store it on key 'default'
Crud::getInstance($pdo); // Just return 'default' instance

Crud::getInstance($pdo,'foo'); // Create new instance and store it on key 'foo'
Crud::getInstance($pdo,'foo'); // Just return 'foo' instance

vuryss 8 年前

Crud

public static function getInstance($connection, $table=null)
  {
    # Verifying if there's a class instance
   if (!isset(self::$crud))
    {
      try
      {
        self::$crud = new Crud($connection, $table);
      }
      catch (Exception $e)
      {
        echo 'Error '.$e->getMessage();
      }
    }
    return self::$crud;
  }

在这种情况下,您必须为不同的表/连接使用新的CRUD实例。不要使用“getInstance”,而是使用 new Crud(...)