PHP基于MySQLI函数封装的数据库连接工具类【定义与用法】

本文实例讲述了PHP基于MySQLI函数封装的数据库连接工具类。分享给大家供大家参考，具体如下：

mysql.class.php：

<?php
class mysql
{
  private $mysqli;
  private $result;
  /**
   * 数据库连接
   * @param $config 配置数组
   */
  public function connect($config)
  {
    $host = $config["host"];    //主机地址
    $username = $config["username"];//用户名
    $password = $config["password"];//密码
    $database = $config["database"];//数据库
    $port = $config["port"];    //端口号
    $this->mysqli = new mysqli($host, $username, $password, $database, $port);
  }
  /**
   * 数据查询
   * @param $table 数据表
   * @param null $field 字段
   * @param null $where 条件
   * @return mixed 查询结果数目
   */
  public function select($table, $field = null, $where = null)
  {
    $sql = "SELECT * FROM {$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;
  }
}

使用方法

<?php
require_once "mysql.class.php";
/* 配置连接参数 */
$config = array(
  "type" => "mysql",
  "host" => "localhost",
  "username" => "woider",
  "password" => "3243",
  "database" => "php",
  "port" => "3306"
);
/* 连接数据库 */
$mysql = new mysql();
$mysql->connect($config);
/* 查询数据 */
//1、查询所有数据
$table = "mysqli";//数据表
$num = $mysql->select($table);
echo "共查询到" . $num . "条数据";
print_r($mysql->fetchAll());
//2、查询部分数据
$field = array("username", "password"); //过滤字段
$where = "id % 2 =0";          //过滤条件
$mysql->select($table, $field, $where);
print_r($mysql->fetchAll());
/* 插入数据 */
$table = "mysqli";//数据表
$data = array(  //数据数组
  "username" => "admin",
  "password" => sha1("admin")
);
$id = $mysql->insert($table, $data);
echo "插入记录的ID为" . $id;
/* 修改数据 */
$table = "mysqli";//数据表
$data = array(
  "password" => sha1("nimda")
);
$where = "id = 44";
$rows = $mysql->update($table, $data, $where);
echo "受影响的记录数量为" . $rows . "条";
/* 删除数据 */
$table = "mysqli";
$where = "id = 45";
$rows = $mysql->delete($table, $where);
echo "已删除" . $rows . "条数据";

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