是否有可能有多个例外的Try/Catch Throw

我有以下代码,我想知道我是否可以使用try&catch如下:

class fun_database implements idbInfo{
    private $srvr=idbInfo::srvr_name;
    private $usr=idbInfo::usrnm;
    private $pass=idbInfo::psswrd;
    private $db=idbInfo::db_name;

    public function connct(){
        $hookup = new mysqli($this->srvr, $this->usr, $this->pass, $this->db);

        if ($hookup->connect_errno)     
        {
            throw new Exception("Error Processing Request", 1);
        }
    }

    public function sql_require_all($table_name, $table_col){
        $hookup = new connct();

        $result = $hookup->query("SELECT $table_col FROM $table_name");
            if($hookup->error()){
               throw new Exception("Error Processing Request", 1);
            }
        return $result->num_rows;
    }
}

这是一个与mysql的简单连接,并在那里执行一些查询.这是以上函数的实际调用:

$conn = new fun_database();
    try{
        $result = $conn->sql_require_all('wordtypes', 'types');
    }
    catch(Exception $err){
        echo "Problems at:". $err->getMessage();
    }
    return "".$result."";

我要问的是一点理论.很可能这段代码不工作(我还没有测试).我只是想知道是否可以通过"尝试"'捕获'两个异常(因为你可以看到第一个'throw'在fun_database的第二个方法中,第二个'throw'在第一个方法中同样的对象,只从第二种方法调用).

抱歉让它变得太复杂但仍然无法弄清楚这个try/catch的结构是否有效.

你只能捕捉不同类型的例外......

class fun_database implements idbInfo{
private $srvr=idbInfo::srvr_name;
private $usr=idbInfo::usrnm;
private $pass=idbInfo::psswrd;
private $db=idbInfo::db_name;

public function connct(){
    $hookup = new mysqli($this->srvr, $this->usr, $this->pass, $this->db);

    if ($hookup->connect_errno)     
    {
        throw new DomainException("Error Processing Request", 1);
    }
}

public function sql_require_all($table_name, $table_col){
    $hookup = new connct();

    $result = $hookup->query("SELECT $table_col FROM $table_name");
        if($hookup->error()){
           throw new Exception("Error Processing Request", 1);
        }
    return $result->num_rows;
}
}

然后:

try{
    $conn = new fun_database();
    $result = $conn->sql_require_all('wordtypes', 'types');
}
catch(DomainException $err){
    echo "This Problem at:". $err->getMessage();
}
catch(Exception $err){
    echo "That Problem at:". $err->getMessage();
}
return "".$result."";

虽然我相信,你需要在try块中进行类实例化.