PHP连接MySQLI类，已连贯操作形式请求内部方法

<?php

/**

* Created by PhpStorm.

* User: 宇晨PHP培训 www.hnphp.net

* Date: 2017/4/20

* Time: 9:06

*/

class MySQL

{

private static $Obj;//作为实例化对象的存储

private static $DB;//定义一个私有的静态属性存放MySQL对象

private $SQLArr=array();//定义处理之后SQL语句代码片段

public $TableName='';//定义当前模型所使用的表名

private function __construct()//把构造方法设置为私有的禁止外部实例化调用

{

self::$DB=new mysqli(DBHOST,DBUSER,DBPWD,DBNAME,DBPORT);

self::$DB->set_charset(DBCODE);

if(self::$DB->connect_errno>0)

{

echo '<hr>错误连接编码：'.self::$DB->connect_errno.'<br>';

echo '错误连接信息：'.self::$DB->connect_error.'<hr>';

exit();

}

$this->clearData();//清除SQL语句片段

}

//清除SQL语句片段

private function clearData()

{

$this->SQLArr['Fields']='*';

$this->SQLArr['Where']='';

$this->SQLArr['Order']='';

$this->SQLArr['Limit']='';

$this->SQLArr['Data']='';

$this->SQLArr['Join']='';

}

private function __clone()//把克隆方法设置为私有的禁止外部克隆当前对象

{

return false;

}

public static function CallRun()//调用运行当前类

{

if(!(self::$Obj instanceof self))

{

self::$Obj=new self;

}

return self::$Obj;

}

//定义SQL语句的表名

public function table($Param='')

{

$this->TableName=$Param;

return self::$Obj;

}

//定义SQL语句的具体字段

public function fields($Param='')

{

$this->SQLArr['Fields']=empty($Param)?'*':$Param;

return self::$Obj;

}

//定义SQL语句where条件的片段语句

public function where($Param=array())

{

$Str=' where 1 ';

if(!empty($Param) && is_array($Param))

{

foreach($Param as $key=>$val)

{

$Type=empty($val[0])?'=':$val[0].' ';

$Value=$val[1]==''||$val[1]===false?'':$val[1].' ';

$Mark=empty($val[2])?' And ':$val[2].' ';

$Str.=$Mark.$key.' '.$Type.' '.$Value;

}

}

$this->SQLArr['Where']=$Str;

return self::$Obj;

}

//定义SQL语句 join 代码片段

public function join($Param='')

{

$this->SQLArr['Join']=$Param;

return self::$Obj;

}

//定义SQL语句 Order By 排序的节点代码片段

public function order($Param='')

{

$Str='';

if(!empty($Param))

{

$Str=' order by '.$Param;

}

$this->SQLArr['Order']=$Str;

return self::$Obj;

}

//定义SQL语句 limit 代码片段

public function limit($Param='')

{

$Str='';

if(!empty($Param))

{

$Str=' limit '.$Param;

}

$this->SQLArr['Limit']=$Str;

return self::$Obj;

}

//作为SQL语句的末级节点,把所有拼接起来的SQL语句片段进行整合对接 单条 select 语句获取形式

public function find()

{

$Str=$this->SQLArr['Limit'];

if(empty($this->SQLArr['Limit']))

{

$Str=' Limit 1';

}

$Result=$this->SQLQuery($Str);

return $Result->fetch_assoc();

}

//获取多条数据

public function select()

{

$Str='';

if(!empty($this->SQLArr['Limit']))

{

$Str=$this->SQLArr['Limit'];

}

$Result=$this->SQLQuery($Str);

$List=array();

while($Row=$Result->fetch_assoc())

{

$List[]=$Row;

}

return $List;

}

private function SQLQuery($Str='')

{

$SQL='select '.$this->SQLArr['Fields'].' from '.DBPREFIX.$this->TableName.$this->SQLArr['Join'].$this->SQLArr['Where'].$this->SQLArr['Order'].$Str;

//echo $SQL.'<hr>';

return $this->query($SQL);

}

//处理添加或更新时的key value对数据

public function data($Param=array())

{

$Arr=array();

if(!empty($Param) && is_array($Param))

{

foreach($Param as $key => $val)

{

$Arr['Key'][]=trim($key);

$Arr['Val'][]='"'.trim($val).'"';

}

}

$this->SQLArr['Data']=$Arr;

return self::$Obj;

}

//数据添加

public function insert()

{

if(empty($this->SQLArr['Data']) && !is_array($this->SQLArr['Data']))

{

return false;

}

$KeyStr=implode(',',$this->SQLArr['Data']['Key']);

$ValStr=implode(',',$this->SQLArr['Data']['Val']);

$SQL='insert into '.DBPREFIX.$this->TableName.' ('.$KeyStr.') values ('.$ValStr.')';

return $this->query($SQL);

}

//获取添加数据的ID

public function insertid()

{

return self::$DB->insert_id;

}

//更新数据

public function update()

{

if(empty($this->SQLArr['Data']) && !is_array($this->SQLArr['Data']))

{

return false;

}

$Arr='';

foreach($this->SQLArr['Data']['Key'] as $key=>$val)

{

$Arr[]=$val.'='.$this->SQLArr['Data']['Val'][$key];

}

$Str=implode(',',$Arr);

$SQL='update '.DBPREFIX.$this->TableName.' set '.$Str.$this->SQLArr['Where'].$this->SQLArr['Limit'];

//echo $SQL;

return $this->query($SQL);

}

//删除数据

public function delete()

{

if(empty($this->SQLArr['Limit']))

{

$this->SQLArr['Limit']=' Limit 1';

}

$SQL='delete from '.DBPREFIX.$this->TableName.$this->SQLArr['Where'].$this->SQLArr['Limit'];

//echo $SQL;

return $this->query($SQL);

}

public function query($SQL)

{

$this->clearData();//清除SQL语句片段

$Result=self::$DB->query($SQL);

if(self::$DB->errno>0)

{

echo '<hr>SQL语句错误编号：'.self::$DB->errno.'<br>';

echo 'SQL语句错误描述：'.self::$DB->error.'<hr>';

}

return $Result;

}

public function __destruct()

{

self::$DB->close();

}

}

//$Obj1=MySQL::CallRun();

//$Obj2=MySQL::CallRun();

//echo $Obj1->insertid();

//var_dump($Obj1);

//var_dump($Obj2);