一个简单的数据库连接和文本缓存综合类

WBOY

发布： 2016-07-25 08:49:36

原创

884 人浏览过

没什么特色，就是把数据库连接和文本缓存封装在一个类里面了

class Db{
protected $_connect;
protected $_db = Array();
protected $_cache = Array();
public function __construct($args){
list($this->_db,$this->_cache) = $args;
}
protected function connect($db){
$this->_connect = mysql_connect($db['hostname'],$db['username'],$db['password']);
mysql_set_charset('UTF8');
mysql_select_db($db['databasename'],$this->_connect);
}
/**
*作用：获取表中数据，并将所查询到的数据格式化返回，返回格式是数组形式！
*$sql：传入的待执行的SQL语句，必须而且只能是SELECT
*
*/
public function fetch($sql){
$result = '';
if(isset($this->_cache['expire'])){
$name = md5(strtolower(str_replace(' ','',$sql)));
$dir = substr($name,0,2);
$dir = $this->_cache['dir'].'/'.$dir;
!is_dir($dir) && mkdir($dir,0777);
!is_dir($dir) && mkdir($dir,0777);
$this->_cache['path'] = $dir.'/'.$name;
if(is_file($this->_cache['path']) && $this->check_expire()){
$result = $this->get();
}
}
if($result == ''){
$data = $this->exec($sql);
$result = Array();
while($result[] = mysql_fetch_array($data,MYSQL_ASSOC)){} //去除索引
mysql_free_result($data);
array_pop($result);
isset($this->_cache['expire']) && $this->write($result);
}
return $result;
}
/**
*作用：执行所有的SQL语句，但不包括SELECT！
*$sql：传入的待执行的SQL语句，不能为SELECT
*返回值：TRUE OR FALSE
*/
public function exec($sql){
if($this->_connect === null) $this->connect($this->_db); //进行数据链接
if( $result = mysql_query($sql, $this->_connect) ){
return $result;
}else{
die("{$sql}
执行错误: " . mysql_error());
}
}
/**
*作用：执行数据库插入语句，只能是INSERT语句！
*$v：传入的待执行的条件，是数组格式table代表待执行插入的表，row是字段，value是待插入的值
*返回值：mysql_insert_id() OR FALSE
*/
public function insert($table,$field,$ignore = 0){
$D = Array('field'=>'','val'=>'');
foreach($field AS $key => $v){
$D['field'] .= $key.',';
$D['val'] .= "'{$this->escape($v)}',";
}
$D['field'] = rtrim($D['field'],',');
$D['val'] = rtrim($D['val'],',');
$ignore = $ignore > 0 ? 'IGNORE' : '';
$sql = "INSERT {$ignore} INTO {$this->_db['perfix']}{$table}({$D['field']}) VALUES({$D['val']})";
if($this->exec($sql)){
$insert_id = mysql_insert_id();
return is_numeric($insert_id) ? $insert_id : TRUE;
}else{
return FALSE;
}
}
public function update($table,$field){
$D = Array('where'=>'','str'=>'');
$index = 0;
foreach($field AS $key => $v){
$index == 0 ? $D['where'] = "{$key} = '{$this->escape($v)}'" : $D['str'] .= "{$key} = '{$this->escape($v)}',";
$index++;
}
$D['str'] = rtrim($D['str'],',');
$sql = "UPDATE {$this->_db['perfix']}{$table} SET {$D['str']} WHERE {$D['where']}";
return $this->exec($sql);
}
public function delete($table,$field){
$str = '';
foreach($field AS $key => $v){
$str = "{$key} = '{$v}'";
}
$sql = 'DELETE FROM '.$this->_db['perfix'].$table.' WHERE '.$str.' LIMIT 1';
return $this->exec($sql);
}
public function sum($table,$condition){
$totle = $this->fetch('SELECT COUNT(*) AS totle FROM '.$this->_db['perfix'].$table.' WHERE '.$condition);
return $totle[0]['totle'];
}
/**
*作用：对输入特殊字符进行过滤
*$v：待传入检测的参数
*返回值：检测完的参数
*/
public function escape($v){
return mysql_real_escape_string($v);
}
/*
*作用：进行缓存判断
*/
public function cache($name,$expire=100000000){
$this->_cache['expire'] = $expire;
return $this;
}
public function check_expire(){
return (filemtime($this->_cache['path']) + $this->_cache['expire']) > strtotime("now");
}
public function write($data){
$f = fopen($this->_cache['path'], 'w');
if ($f) {
flock($f, LOCK_EX);
fseek($f, 0);
ftruncate($f, 0);
$tmp = fwrite($f, serialize($data));
if (!($tmp === false)) {
$result = true;
}
fclose($f);
}
chmod($this->_cache['path'],0777);
}
public function get(){
$f = fopen($this->_cache['path'], 'r');
$data = fread($f,filesize($this->_cache['path']));
fclose($f);
return unserialize($data);
}
public function delete_dir($dir = ''){
$dir = empty($dir) ? $this->_cache['dir'] : $dir;
!is_dir($dir) && exit;
$d = opendir($dir);
$i = 0;
while(($file = readdir($d)) !== false){
$path = $dir.'/'.$file;
if($i > 1) is_file($path) ? unlink($path) : $this->delete_dir($path);
$i++;
}
closedir($d);
rmdir($dir);
}
public function __destruct(){
isset($this->_connect) && mysql_close($this->_connect);
}
}

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