本文实例讲述了一款简单实用的php操作mysql数据库类。分享给大家供大家参考。具体如下：
/*
本款数据库连接类，他会自动加载sql防注入功能，过滤一些敏感的sql查询关键词，同时还可以增加判断字段 show table status的性质与show table类 获取数据库所有表名等。*/
@ini_set('mysql.trace_mode','off');
class mysql
{
public $dblink;
public $pconnect;
private $search = array('/union(s*(/*.**/)?s*)+select/i', '/load_file(s*(/*.**/)?s*)+(/i', '/into(s*(/*.**/)?s*)+outfile/i');
private $replace = array('union select', 'load_file (', 'into outfile');
private $rs;
function __construct($hostname,$username,$userpwd,$database,$pconnect=false,$charset='utf8')
{
define('allowed_htmltags', '<html><embed><title><meta><body><a><p><br><hr><h1><h2><h3><h4><h5><h6><font><u><i><b><strong><div><span><ol><ul><li><img><table><tr><td><map>');
$this->pconnect=$pconnect;
$this->dblink=$pconnect?mysql_pconnect($hostname,$username,$userpwd):mysql_connect($hostname,$username,$userpwd);
(!$this->dblink||!is_resource($this->dblink)) && fatal_error("connect to the database unsuccessfully!");
@mysql_unbuffered_query("set names {$charset}");
if($this->version()>'5.0.1')
{
@mysql_unbuffered_query("set sql_mode = ''");
}
@mysql_select_db($database) or fatal_error("can not select table!");
return $this->dblink;
}
function query($sql,$unbuffered=false)
{
//echo $sql.'<br>';
$this->rs=$unbuffered?mysql_unbuffered_query($sql,$this->dblink):mysql_query($sql,$this->dblink);
//(!$this->rs||!is_resource($this->rs)) && fatal_error("execute the query unsuccessfully! error:".mysql_error());
if(!$this->rs)fatal_error('在执行sql语句 '.$sql.' 时发生以下错误:'.mysql_error());
return $this->rs;
}
function fetch_one($sql)
{
$this->rs=$this->query($sql);
return dircms_strips教程lashes($this->filter_pass(mysql_fetch_array($this->rs,mysql_assoc)));
}
function get_maxfield($filed='id',$table) // 获取$table表中$filed字段的最大值
{
$r=$this->fetch_one("select {$table}.{$filed} from `{$table}` order by `{$table}`.`{$filed}` desc limit 0,1");
return $r[$filed];
}
function fetch_all($sql)
{
$this->rs=$this->query($sql);
$result=array();
while($rows=mysql_fetch_array($this->rs,mysql_assoc))
{
$result[]=$rows;
}
mysql_free_result($this->rs);
return dircms_stripslashes($this->filter_pass($result));
}
function fetch_all_withkey($sql,$key='id')
{
$this->rs=$this->query($sql);
$result=array();
while($rows=mysql_fetch_array($this->rs,mysql_assoc))
{
$result[$rows[$key]]=$rows;
}
mysql_free_result($this->rs);
return dircms_stripslashes($this->filter_pass($result));
}
function last_insert_id()
{
if(($insertid=mysql_insert_id($this->dblink))>0)return $insertid;
else //如果 auto_increment 的列的类型是 bigint，则 mysql_insert_id() 返回的值将不正确.
{
$result=$this->fetch_one('select last_insert_id() as insertid');
return $result['insertid'];
}
}
function insert($tbname,$varray,$replace=false)
{
$varray=$this->escape($varray);
$tb_fields=$this->get_fields($tbname); // 升级一下，增加判断字段是否存在
foreach($varray as $key => $value)
{
if(in_array($key,$tb_fields))
{
$fileds[]='`'.$key.'`';
$values[]=is_string($value)?'''.$value.''':$value;
}
}
if($fileds)
{
$fileds=implode(',',$fileds);
$fileds=str_replace(''','`',$fileds);
$values=implode(',',$values);
$sql=$replace?"replace into {$tbname}({$fileds}) values ({$values})":"insert into {$tbname}({$fileds}) values ({$values})";
$this->query($sql,true);
return $this->last_insert_id();
}
else return false;
}
function update($tbname, $array, $where = '')
{
$array=$this->escape($array);
if($where)
{
$tb_fields=$this->get_fields($tbname); // 增加判断字段是否存在
$sql = '';
foreach($array as $k=>$v)
{
if(in_array($k,$tb_fields))
{
$k=str_replace(''','',$k);
$sql .= ", `$k`='$v'";
}
}
$sql = substr($sql, 1);
if($sql)$sql = "update `$tbname` set $sql where $where";
else return true;
}
else
{
$sql = "replace into `$tbname`(`".implode('`,`', array_keys($array))."`) values('".implode("','", $array)."')";
}
return $this->query($sql,true);
}
function mysql_delete($tbname,$idarray,$filedname='id')
{
$idwhere=is_array($idarray)?implode(',',$idarray):intval($idarray);
$where=is_array($idarray)?"{$tbname}.{$filedname} in ({$idwhere})":" {$tbname}.{$filedname}={$idwhere}";
return $this->query("delete from {$tbname} where {$where}",true);
}
function get_fields($table)
{
$fields=array();
$result=$this->fetch_all("show columns from `{$table}`");
foreach($result as $val)
{
$fields[]=$val['field'];
}
return $fields;
}
function get_table_status($database)
{
$status=array();
$r=$this->fetch_all("show table status from `".$database."`"); /////// show table status的性质与show table类似，不过，可以提供每个表的大量信息。
foreach($r as $v)
{
$status[]=$v;
}
return $status;
}
function get_one_table_status($table)
{
return $this->fetch_one("show table status like '$table'");
}
function create_fields($tbname,$fieldname,$size=0,$type='varchar') // 2010-5-14 修正一下
{
if($size)
{
$size=strtoupper($type)=='varchar'?$size:8;
$this->query("alter table `{$tbname}` add `$fieldname` {$type}( {$size} ) not null",true);
}
else $this->query("alter table `{$tbname}` add `$fieldname` mediumtext not null",true);
return true;
}
function get_tables() //获取所有表表名
{
$tables=array();
$r=$this->fetch_all("show tables");
foreach($r as $v)
{
foreach($v as $v_)
{
$tables[]=$v_;
}
}
return $tables;
}
function create_model_table($tbname) //创建一个内容模型表（start：初始只有字段contentid int(20)，用于内容表，/////////////////////// update：2010-5-20 默认加入`content` mediumtext not null,字段）
{
if(in_array($tbname,$this->get_tables())) return false; ///////////////////// 当表名已经存在时，返回 false
if($this->query("create table `{$tbname}` (
`contentid` mediumint(8) not null ,
`content` mediumtext not null,
key ( `contentid` )
) engine = myisam default charset=utf8",true))return true; //////////////////// 成功则返回 true
return false; //////////////失败返回 false
}
function create_table($tbname) //创建一个会员模型空表（初始只有字段userid int(20)，用于会员表，2010-4-26）
{
if(in_array($tbname,$this->get_tables())) return false;
if($this->query("create table `{$tbname}` (
`userid` mediumint(8) not null ,
key ( `userid` )
) engine = myisam default charset=utf8",true))return true;
return false;
}
function escape($str) // 过滤危险字符
{
if(!is_array($str)) return str_replace(array('n', 'r'), array(chr(10), chr(13)),mysql_real_escape_string(preg_replace($this->search,$this->replace, $str), $this->dblink));
foreach($str as $key=>$val) $str[$key] = $this->escape($val);
return $str;
}
function filter_pass($string, $allowedtags = '', $disabledattributes = array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavaible', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragdrop', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterupdate', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmoveout', 'onmouseo教程ver', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload'))
{
if(is_array($string))
{
foreach($string as $key => $val) $string[$key] = $this->filter_pass($val, allowed_htmltags);
}
else
{
$string = preg_replace('/s('.implode('|', $disabledattributes).').*?([s>])/', '', preg_replace('/<(.*?)>/ie', "'<'.preg_replace(array('/网页特效:[^"']*/i', '/(".implode('|', $disabledattributes).")[ ]*=[ ]*["'][^"']*["']/i', '/s+/'), array('', '', ' '), stripslashes('')) . '>'", strip_tags($string, $allowedtags)));
}
return $string;
}
function drop_table($tbname)
{
return $this->query("drop table if exists `{$tbname}`",true);
}
function version()
{
return mysql_get_server_info($this->dblink);
}
}
希望本文所述对大家的PHP程序设计有所帮助。