PHP implements a complete example of the Model base class based on mysqli_php skills

The example in this article describes the PHP implementation of the Model base class based on mysqli. Share it with everyone for your reference, the details are as follows:

DB.class.php

<&#63;php
  //数据库连接类
  class DB {
     //获取对象句柄
     static public function getDB() {
       $_mysqli = new mysqli(DB_HOST,DB_USER,DB_PASS,DB_NAME);
       if (mysqli_connect_errno()) {
          echo '数据库连接错误！错误代码：'.mysqli_connect_error();
          exit();
       }
       $_mysqli->set_charset('utf8');
       return $_mysqli;
     }
     //清理，释放资源
     static public function unDB(&$_result, &$_db) {
       if (is_object($_result)) {
          $_result->free();
          $_result = null;
       }
       if (is_object($_db)) {
          $_db->close();
          $_db = null;
       }
     }
  }
&#63;>

Model.class.php

<&#63;php
  //模型基类
  class Model {
     //执行多条SQL语句
     public function multi($_sql) {
       $_db = DB::getDB();
       $_db->multi_query($_sql);
       DB::unDB($_result = null, $_db);
       return true;
     }
     //获取下一个增值id模型
     public function nextid($_table) {
       $_sql = "SHOW TABLE STATUS LIKE '$_table'";
       $_object = $this->one($_sql);
       return $_object->Auto_increment;
     }
     //查找总记录模型
     protected function total($_sql) {
       $_db = DB::getDB();
       $_result = $_db->query($_sql);
       $_total = $_result->fetch_row();
       DB::unDB($_result, $_db);
       return $_total[0];
     }
     //查找单个数据模型
     protected function one($_sql) {
       $_db = DB::getDB();
       $_result = $_db->query($_sql);
       $_objects = $_result->fetch_object();
       DB::unDB($_result, $_db);
       return Tool::htmlString($_objects);
     }
     //查找多个数据模型
    protected function all($_sql) {
       $_db = DB::getDB();
       $_result = $_db->query($_sql);
       $_html = array();
       while (!!$_objects = $_result->fetch_object()) {
          $_html[] = $_objects;
       }
       DB::unDB($_result, $_db);
       return Tool::htmlString($_html);
     }
     //增删修模型
     protected function aud($_sql) {
       $_db = DB::getDB();
       $_db->query($_sql);
       $_affected_rows = $_db->affected_rows;
       DB::unDB($_result = null, $_db);
       return $_affected_rows;
     }
  }
&#63;>

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