php实现mysql封装类示例

php封装mysql类

复制代码

代码如下:

<?php

class

Mysql

{

private

$host

private

$user

private

$pwd

private

$dbName

private

$charset

private

$conn

=

null

public

function

__construct()

{

$this->host

=

'localhost'

$this->user

=

'root'

$this->pwd

=

'root'

$this->dbName

=

'test'

$this->connect($this->host,$this->user,$this->pwd)

$this->switchDb($this->dbName)

$this->setChar($this->charset)

}

//负责链接

private

function

connect($h,$u,$p)

{

$conn

=

mysql_connect($h,$u,$p)

$this->conn

=

$conn

}

//负责切换数据库

public

function

switchDb($db)

{

$sql

=

'use'

.

$db

$this->query($sql)

}

//负责设置字符集

public

function

setChar($char)

{

$sql

=

'set

names'

.

$char

$this->query($sql)

}

//负责发送sql查询

public

function

query($sql)

{

return

mysql_query($sql,$this->conn)

}

//负责获取多行多列的select结果

public

function

getAll($sql)

{

$list

=

array()

$rs

=

$this->query($sql)

if

(!$rs)

{

return

false

}

while

($row

=

mysql_fetch_assoc($rs))

{

$list[]

=

$row

}

return

$list

}

public

function

getRow($sql)

{

$rs

=

$this->query($sql)

if(!$rs)

{

return

false

}

return

mysql_fetch_assoc($rs)

}

public

function

getOne($sql)

{

$rs

=

$this->query($sql)

if

(!$rs)

{

return

false

}

return

mysql_fetch_assoc($rs)

return

$row[0]

}

public

function

close()

{

mysql_close($this->conn)

}

}

echo

'<pre>'

$mysql

=

new

Mysql()

print_r($mysql)

$sql

=

"insert

into

stu

values

(4,'wangwu','99998')"

if($mysql->query($sql)){

echo

"query成功"

}else

{

echo

"失败"

}

echo

"<br

/>"

$sql

=

"select

*

from

stu"

$arr

=

$mysql->getAll($sql)

print_r($arr)

?>

class demo

{

    function __destruct()

    {

        $DB->close()     // $DB哪里来的？应该是$this->DB->close()吧

    }

    public function __construct()

    {

        $DB = new DB_MySQL     // 这属于函数内部变量，函数执行完就消失了。所以应该用$this->DB = new DB_MySQL

        $DB->connect(servername, dbusername, dbpassword, dbname, usepconnect)     // 同理，需要改成$this->DB，参数也有问题吧，还是你为避免泄露sql账号密码故意这么写的？

    }

    function test()

    {

        $sql1 = "SELECT * FROM tab limit 1"

        $txt = $DB->fetch_one_array($sql1)     // 同理，需要改成$this->DB

        return  $txt['id'] 

    }

}

$person = new demo

echo $person->test()

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