<"SELECT * FROM {$table}";
    if (!empty($field)) {
      $field = '`' . implode('`,`', $field) . '`';
      $sql = str_replace('*', $field, $sql);
    }
    if (!empty($where)) {
      $sql = $sql . ' WHERE ' . $where;
    }
    $this->result = $this->mysqli->query($sql);
    return $this->result->num_rows;
  }
  /**
   * @return mixed 获取全部结果
   */
  public function fetchAll()
  {
    return $this->result->fetch_all(MYSQLI_ASSOC);
  }
  /**
   * 插入数据
   * @param $table 数据表
   * @param $data 数据数组
   * @return mixed 插入ID
   */
  public function insert($table, $data)
  {
    foreach ($data as $key => $value) {
      $data[$key] = $this->mysqli->real_escape_string($value);
    }
    $keys = '`' . implode('`,`', array_keys($data)) . '`';
    $values = '\'' . implode("','", array_values($data)) . '\'';
    $sql = "INSERT INTO {$table}( {$keys} )VALUES( {$values} )";
    $this->mysqli->query($sql);
    return $this->mysqli->insert_id;
  }
  /**
   * 更新数据
   * @param $table 数据表
   * @param $data 数据数组
   * @param $where 过滤条件
   * @return mixed 受影响记录
   */
  public function update($table, $data, $where)
  {
    foreach ($data as $key => $value) {
      $data[$key] = $this->mysqli->real_escape_string($value);
    }
    $sets = array();
    foreach ($data as $key => $value) {
      $kstr = '`' . $key . '`';
      $vstr = '\'' . $value . '\'';
      array_push($sets, $kstr . '=' . $vstr);
    }
    $kav = implode(',', $sets);
    $sql = "UPDATE {$table} SET {$kav} WHERE {$where}";
    $this->mysqli->query($sql);
    return $this->mysqli->affected_rows;
  }
  /**
   * 删除数据
   * @param $table 数据表
   * @param $where 过滤条件
   * @return mixed 受影响记录
   */
  public function delete($table, $where)
  {
    $sql = "DELETE FROM {$table} WHERE {$where}";
    $this->mysqli->query($sql);
    return $this->mysqli->affected_rows;
  }
}

<"_blank" href="https://www.jb51.net/Special/768.htm">php+mysqli数据库程序设计技巧总结》、《php面向对象程序设计入门教程》、《PHP数组(Array)操作技巧大全》、《PHP基本语法入门教程》、《php字符串(string)用法总结》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》

希望本文所述对大家PHP程序设计有所帮助。