PHP学习实例，数据库封装类。
<?php
class Core{
/*对数组进行继承*/
static function inHerit($arr_orgin,$arr_output){
return array_merge($arr_orgin,$arr_output);
}
/*打印错误*/
static function throwError($errmsg){
echo '<p>error:'.$errmsg.'</p>';
exit();
}
}
?>
<?php
class db{
private $result = array();
private $connector = array();
private $configs = array();
private $active = 0;
private $default_config = array(
'dbtype' => 'mysql',
'index' => 0,'user' => 'root', 'pwd' => '' ,'host' => 'localhost' ,'port'=> 3306,'charset' => 'utf8' ,'dbname' => null
);
/*初始化*/
public function __construct($config = array()){
if($config) $this->connect($config);
}
public function __destruct(){
foreach($this->connector as $index => $connect)
$this->{'_'.$this->configs[$index]['dbtype'].'_close'}($connect);
}
private function _mysql_close($connect){
mysqli_close($connect);
}
/*选择连接*/
public function selectConnect($index){
return isset($this->connector[$index]) && (($this->active = $index) || true);
}
/*建立连接*/
public function connect($config){
(!isset($config['index'])) && $config['index'] = $this->default_config['index']++ ;
$config = Core::inHerit($this->default_config,$config);
!in_array($config['dbtype'],array('mysql')) && Core::throwError('未支持的数据库类型');
extract($config);
$this->configs[$index] = $config;
$this->{'_'.$config['dbtype'].'_connect'}($user, $pwd,$host,$dbname,$charset,$index,$port);
}
private function _mysql_connect($user = 'root', $pwd = '' ,$host = 'localhost' ,$dbname = null,$charset = 'utf8' ,$index = 0 ,$port = 3306){
$this->connector[$index] = mysqli_connect ( $host, $user, $pwd , null, $port) or Core::throwError(mysql_error());
$this->active = $index;
if($dbname) $this->selectDb($dbname,$charset);
}
/*取得当前连接*/
private function _getConnect(){
return $this->connector[$this->active];
}
/*取得当前连接使用的数据库类型 带参数自动拼接为函数名*/
private function _getDbTypeFunc($funcname = null){
$dbtype = $this->configs[$this->active]['dbtype'];
return $funcname?'_'.$dbtype.'_'.$funcname:$dbtype;
}
/*选择数据库*/
public function selectDb($dbname,$charset){
mysqli_select_db($this->_getConnect(),$dbname) or Core::throwError(mysql_error());
$this->_mysql_query('set names '.$charset);
}
/*执行语句*/
private function _mysql_query($sql){
$result = mysqli_query($this->_getConnect(),$sql) or Core::throwError(mysql_error());
return $result;
}
private function _mysql_bind_by_name($sql , $sqlv){
$sql_param = array();
$getparam = $getparam2 = '\w+?';// $getparam = array_keys($sqlv); implode('|',$getparam);
preg_match_all('/:('.$getparam.')\b/iU',$sql,$getparam) or Core::throwError('参数绑定错误');
$getparam = $getparam[1];
$getparam = array_flip($getparam);
count($getparam) != count($sqlv) || array_diff_key($getparam,$sqlv) && Core::throwError('参数不匹配');
$sql = preg_replace('/:('.$getparam2.')\b/iU','?',$sql) ;
$sqlv = array_merge($getparam,$sqlv);
unset($getparam2);
unset($getparam);
$stmt = mysqli_prepare($this->_getConnect(),$sql) or Core::throwError('wrong sql:'.$sql);
$ptype = '';
$bindparam = array($stmt,'');
foreach ($sqlv as $k => $v){
$ptype .= $this->_getParamType($k);
$bindparam[] = $v;
}
$bindparam[1] = $ptype;
call_user_func_array('mysqli_stmt_bind_param',$bindparam);
return $this->_mysql_stmt_exec($stmt,$sql);
}
private function _mysql_bind_in_sort(){
$argus = func_get_args() ;
$sql = array_shift($argus);
$stmt = mysqli_prepare($this->_getConnect(),$sql) or Core::throwError('wrong sql:'.$sql);
$pcount = mysqli_stmt_param_count($stmt);
$pcount != count($argus) && Core::throwError('参数不匹配');
$ptype = str_repeat('s',$pcount);
array_splice($argus, 0, 0 ,array($stmt,$ptype));
call_user_func_array('mysqli_stmt_bind_param',$argus);
return $this->_mysql_stmt_exec($stmt,$sql);
}
private function _mysql_stmt_exec($stmt,$sql){
mysqli_stmt_execute($stmt);
if($this->isSelect($sql)){ ///返回值绑定
mysqli_stmt_bind_result($stmt,$a);
while ($stmt->fetch()) {
print_r($a);
echo '<br/>';
}
}
$stmt->close();
}
/*根据参数形式使用不同函数*/
private function _mysql_iquery($sql , $sqlv = array()){
if ($sqlv){
if (is_array($sqlv))
return $this->_mysql_bind_by_name($sql , $sqlv);
else{
$argus = func_get_args() ;
return call_user_func_array(array($this,'_mysql_bind_in_sort'),$argus);
}
}else{
return $this->_mysql_query($sql,$sqlv);
}
}
/*根据键名前缀区分数据类型*/
private function _getParamType($key){
$r = 's';
/*首字母小写 第二个字母大写 则第一个字母为模式前缀*/
$mode = array(
'i' => 'i','s' => 's','d' => 'd','b' => 'b'
);
if (strlen($key) >= 2 && $key[0] == strtolower($key[0]) && $key[1] == strtoupper($key[1]) && in_array($key[0],$mode))
$r = $mode[$key[0]];
return $r;
}
/*分析sql语句 判断行为*/
private function _cmdType($sql){
return substr(strtolower($sql),0,strpos($sql,' '));
}
/*分析sql语句是否为select语句*/
private function isSelect($sql){
return 'select' == $this->_cmdType($sql);
}
public function query($sql , $sqlv = array()){
$func = $this->_getDbTypeFunc('iquery');
$argus = func_get_args() ;
$argus[0] = trim($argus[0]);
return call_user_func_array(array($this,$func),$argus);
}
}
?>
<?php
$d = array(
'dbname' => 'test',
'charset' => 'latin1'
);
$db = new db($d);
//数组方式绑定参数
$sqlv = array('iId1'=>'14','id2' => 30);
$r = $db -> query("select id from toselect where id > :iId1 and id < :id2 ",$sqlv);
//标准方式绑定参数
$r = $db -> query("select content from toselect where id > ? ",13);
var_dump($r);
?>