POD package

Foreword: The PHP7+ version has removed the mysql extension and supports mysqli and PDO by default. Compared with mysqli, PDO supports more database types and pre-query security features that mysqli does not have.

First create a class file 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;
    }
    
    /**
     * 插入数据
     * @return 插入数据后自增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();
    }
    
    /**
     * 删除数据
     * @return 受影响行数
     */
    public function delete($table, $condition){
    
    
        $condition = $this->ArrayToString($condition, 'AND');
        $sql = "DELETE FROM {
      
      $table} WHERE {
      
      $condition}";
        return self::$handler->exec($sql);
    }
    
    /**
     * 更新数据
     * @return 受影响行数
     */
    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);
    }
    

	/**
     * 设置数据查询返回类型，PDO默认键对和索引双重形式返回。
     * @param $fetchMode  PDO::FETCH_* 或者数字
     * PDO::FETCH_ASSOC = 2 返回数组
     * PDO::FETCH_OBJ = 5 返回对象
     */
    private $fetchMode = PDO::FETCH_ASSOC;
    public function setAllFetchMode($fetchMode){
    
    
        $this->fetchMode = $fetchMode;
    }

    /**
     * 查询单条数据
     * @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($sql)->fetch($this->fetchMode);
    }
    
    /**
     * 查询多条数据
     * @return array
     */
    public function result($table, $condition, $fields = '*') {
    
    
        $condition = $this->ArrayToString($condition, 'AND');
        $sql = "SELECT {
      
      $fields} FROM {
      
      $table} WHERE {
      
      $condition}";
        return self::$handler->query($sql)->fetchAll($this->fetchMode);
    }
    
    /**
     * 数组转字符串
     */
    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);
    }
     
    /**
     * 使用了预查询，防SQL注入
     */
    public function safeQuery($table, $condition, $fields = '*'){
    
    
        if(!is_array($condition)){
    
    
            exit('条件必须是数组');
        }
        $str = '';
        foreach ($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 $sth->fetchAll($this->fetchMode);
    }
}

Test code

<?php
//自动加载类
sql_autoload_rigister(function($className){
    
    
	require_once $className.'php';
});
$pdo = new MyPDO();

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

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

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

echo '单行：';
$row = $pdo->row('users', ['name' => '红辣椒']);
print_r($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 '删除条数：'.$pdo->delete('users'," name = '红辣椒'");