本文介紹了表數(shù)據(jù)網(wǎng)關(guān)的定義與作用，它是一種設(shè)計(jì)模式，用于在應(yīng)用程序和數(shù)據(jù)庫(kù)之間傳輸數(shù)據(jù)。文章還詳細(xì)解釋了網(wǎng)關(guān)類(lèi)的功能以及其在應(yīng)用程序中的應(yīng)用場(chǎng)景。閱讀本文能夠?qū)Ρ頂?shù)據(jù)網(wǎng)關(guān)有更深入的了解，并了解它如何與數(shù)據(jù)庫(kù)交互以及在業(yè)務(wù)類(lèi)中的應(yīng)用。
什么是表數(shù)據(jù)網(wǎng)關(guān)？
表數(shù)據(jù)網(wǎng)關(guān)是一種設(shè)計(jì)模式，它由在應(yīng)用程序和數(shù)據(jù)庫(kù)之間傳輸數(shù)據(jù)的類(lèi)表示。因此，類(lèi)只有持久化方法作為操作，即數(shù)據(jù)記錄。
我們還將有另一個(gè)類(lèi)，它是應(yīng)用程序的業(yè)務(wù)類(lèi)，每當(dāng)需要在數(shù)據(jù)庫(kù)中搜索或保存數(shù)據(jù)時(shí)就使用網(wǎng)關(guān)類(lèi)。
在大多數(shù)情況下，表數(shù)據(jù)網(wǎng)關(guān)處理關(guān)系模型，與數(shù)據(jù)庫(kù)的主表具有 1:1 的關(guān)系。
例子
第 1 步 - 目錄系統(tǒng)：
??Table_Data_Gateway ┣ ??class ┃ ┣ ??Product.php ┃ ┗ ??ProductGateway.php ┣ ??config ┃ ┗ ??config.ini ┣ ??database ┃ ┗ ??product.db ┗ ??index.php
第 2 步 - 數(shù)據(jù)庫(kù)配置文件：
host = name = database/product.db user = pass = type = sqlite
第 3 步 - 數(shù)據(jù)庫(kù)：
CREATE TABLE product( id INTEGER PRIMARY KEY NOT NULL, description TEXT, stock FLOAT, cost_price FLOAT, sale_price FLOAT, bar_code TEXT, date_register DATE, origin CHAR(1) );
第 4 步 - ProductGateway 類(lèi)：
<?php
class ProductGateway
{
private static $conn;
public function __construct()
{
}
public static function setConnection(PDO $conn)
{
self::$conn = $conn;
}
public function find($id, $class = 'stdClass')
{
$sql = "SELECT * FROM product WHERE id = '$id'";
print "$sql <br>";
$result = self::$conn->query($sql);
return $result->fetchObject($class);
}
public function all($filter = '', $class = 'stdClass')
{
$sql = "SELECT * FROM product";
if( $filter )
{
$sql .= " WHERE $filter";
}
print "$sql <br>";
$result = self::$conn->query($sql);
return $result->fetchAll(PDO::FETCH_CLASS, $class);
}
public function delete($id)
{
$sql = "DELETE FROM product WHERE id = '$id'";
print "$sql <br>";
return self::$conn->query($sql);
}
public function save($data)
{
if( empty($data->id) )
{
$sql = "INSERT INTO product
(description, stock, cost_price, sale_price, bar_code, date_register, origin)
VALUES
('{$data->description}',{$data->stock},{$data->cost_price},{$data->sale_price},
{$data->bar_code},'{$data->date-register}','{$data->origin}')";
}
else
{
$sql = "UPDATE product SET
description = '{$data->description}', stock = '{$data->stock}', cost_price = '{$data->cost_price}',
sale_price = '{$data->sale_price}', bar_code = '{$data->bar_code}', date_register = '{$data->date_register}',
origin = '{$data->origin}'
WHERE id = '{$data->id}'";
}
print "$sql <br>";
return self::$conn->exec($sql);
}
}第 5 步 - 產(chǎn)品類(lèi)別：
<?php
class Product
{
private $data;
public function __construct()
{
}
public static function setConnection( PDO $conn)
{
ProductGateway::setConnection($conn);
}
public function __get($prop)
{
return $this->data[$prop];
}
public function __set($prop, $value)
{
$this->data[$prop] = $value;
}
public static function find($id)
{
$gw = new ProductGateway;
return $gw->find($id, 'Product');
}
public static function all($filter = '')
{
$gw = new ProductGateway;
return $gw->all($filter, 'Product');
}
public function save()
{
$gw = new ProductGateway;
return $gw->save( (object) $this->data);
}
public function delete()
{
$gw = new ProductGateway;
return $gw->delete($this->id);
}
public function getProfitMargin()
{
return (($this->sale_price - $this->cost_price)/$this->cost_price)*100;
}
public function registerPurchase($cost, $quantity)
{
$this->cost_price = $cost;
$this->stock += $quantity;
}
}測(cè)試
<?php
require_once 'class/Product.php';
require_once 'class/ProductGateway.php';
try
{
$ini = parse_ini_file('config/config.ini');
$dbname = $ini['name'];
$conn = new PDO('sqlite:'.$dbname);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
Product::setConnection($conn);
$product = new Product;
}
catch(Exception $e)
{
print $e->getMessage();
}在數(shù)據(jù)庫(kù)中記錄產(chǎn)品：
$product->description = 'Juice';
$product->stock = 8;
$product->cost_price = 12;
$product->sale_price = 18;
$product->bar_code = '123123123';
$product->origin = 'S';
$product->date_register = date('Y-m-d');
$product->save();從數(shù)據(jù)庫(kù)更新產(chǎn)品：
$update = $product::find(1); $update->description = "Grape Juice"; $update->save($product);
列出產(chǎn)品：
foreach( $product::all() as $p )
{
print $p->description . ' ';
print $p->cost_price . ' ';
print $p->sale_price . "<br>";
}經(jīng)營(yíng)方式：
文章來(lái)源：http://www.zghlxwxcb.cn/article/417.html
$p = $product::find(1); $p->registerPurchase(24,2); //(cost,quantity) $p->save($product); print $p->getProfitMargin();
文章來(lái)源地址http://www.zghlxwxcb.cn/article/417.html
到此這篇關(guān)于了解表數(shù)據(jù)網(wǎng)關(guān)的工作原理與應(yīng)用場(chǎng)景 | PHP 設(shè)計(jì)模式:表數(shù)據(jù)網(wǎng)關(guān)的文章就介紹到這了,更多相關(guān)內(nèi)容可以在右上角搜索或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！
