POD類封裝

前言：PHP7+版本已經移除了mysql擴展，默認支持mysqli和PDO。相較mysqli來說，PDO支持更多的數據庫類型和預查詢安全功能是mysqli不具備的。

首先建立一個類文件MyPDO.php。

<?php

class MyPDO {
    
    private static $handler;
    
    public function __construct($host = '127.0.0.1', $username = 'root',
     $passwd = '', $dbname = 'test') {
        if (!self::$handler) {
            self::$handler = new PDO("mysql:host=$host;dbname=$dbname", $username, $passwd);
            self::$handler->query("SET NAMES UTF8");
        }
        return self::$handler;
    }
    
    /**
     * 插入數據
     * @return 插入數據後自增id
     */
    public function insert($table, $data){
        $fields = implode(',', array_keys($data));
        $values = implode("','", array_values($data));
        $sql = "INSERT INTO {$table} ( {$fields})  VALUES ( '{$values}' )";
        self::$handler->exec($sql);
        return self::$handler->lastInsertId();
    }
    
    /**
     * 刪除數據
     * @return 受影響行數
     */
    public function delete($table, $condition){
        $condition = $this->ArrayToString($condition, 'AND');
        $sql = "DELETE FROM {$table} WHERE {$condition}";
        return self::$handler->exec($sql);
    }
    
    /**
     * 更新數據
     * @return 受影響行數
     */
    public function update($table, $data, $condition){
        $data = $this->ArrayToString($data, ',');
        $condition = $this->ArrayToString($condition, 'AND');
        $sql = "UPDATE {$table} SET {$data} WHERE {$condition}";
        return self::$handler->exec($sql);
    }
    

	/**
     * 設置數據查詢返回類型，PDO默認鍵對和索引雙重形式返回。
     * @param $fetchMode  PDO::FETCH_* 或者數字
     * PDO::FETCH_ASSOC = 2 返回數組
     * PDO::FETCH_OBJ = 5 返回對象
     */
    private $fetchMode = PDO::FETCH_ASSOC;
    public function setAllFetchMode($fetchMode){
        $this->fetchMode = $fetchMode;
    }

    /**
     * 查詢單條數據
     * @return array
     */
    public function row($table, $condition, $fields = '*'){
        $condition = $this->ArrayToString($condition, 'AND');
        $sql = "SELECT {$fields} FROM {$table} WHERE {$condition} LIMIT 1";
        return self::$handler->query($sql)->fetch(PDO::FETCH_ASSOC);
    }
    
    /**
     * 查詢多條數據
     * @return array
     */
    public function result($table, $condition, $fields = '*') {
        $condition = $this->ArrayToString($condition, 'AND');
        $sql = "SELECT {$fields} FROM {$table} WHERE {$condition}";
        return self::$handler->query($sql)->fetchAll(PDO::FETCH_ASSOC);
    }
    
    /**
     * 數組轉字符串
     */
    private function ArrayToString($data, $connector){
        if(!is_array($data) ){
            return $data;
        }
        $str = '';
        foreach ($data as $k => $v) {
            $str .= " $k = '$v' $connector";
        }
        return rtrim($str, $connector);
    }
     
    /**
     * 使用了預查詢，防SQL注入
     */
    public function safeQuery($table, $condition, $fields = '*'){
        if(!is_array($condition)){
            exit('條件必須是數組');
        }
        $str = '';
        foreach ($condition as $k => $v) {
            $str .= " $k = :$k AND";
        }
        $sql = "SELECT {$fields} FROM {$table} WHERE ".trim($str,'AND');
        $sth = self::$handler->prepare($sql);
        $sth->execute($condition);
        return $sth->fetchAll(PDO::FETCH_ASSOC);
    }
}

測試代碼

<?php
//自動加載類
sql_autoload_rigister(function($className){
	require_once $className.'php';
});
$pdo = new MyPDO();

echo '插入id：'.$pdo->insert('users', ['name' => '紅辣椒']);
echo '<br>';

echo '插入id：'.$pdo->insert('users', ['name' => '孫悟空']);
echo '<br>';

echo '更新條數：'.$pdo->update('users', ['name' => '琦玉'], ['name' => '孫悟空']);
echo '<br>';
echo '<pre>';

echo '單行：';
$row = $pdo->row('users', ['name' => '紅辣椒']);
print_r($row);

echo '多行：被SQL注入的';
$result1 = $pdo->result('users',['name' => "1' or '1"]);
print_r($result1);

echo '多行：防SQL注入的';
$result2 = $pdo->safeQuery('users',['name' => "1' or '1"]);
print_r($result2);

echo '刪除條數：'.$pdo->delete('users'," name = '紅辣椒'");