小编Jac*_*ood的帖子

我想使用汇编代码来处理一些使用PHP关注性能的关键任务.我怎样才能做到这一点？我之前搜索过,但一无所获.

我有一个简单的代码,无法正确使用引用(多态).

#include <iostream>
#include <string>

class Base {
public:
    Base() {}
    virtual ~Base() {}
    virtual std::string text() const {
        return "Base";
    }
};

class Derived: public Base {
public:
    Derived(Base& _b): b(_b) {}
    virtual ~Derived() {}
    virtual std::string text() const {
        return b.text() + " - Derived";
    }

private:
    Base& b;
};

int main(int argc, char const *argv[])
{
    Base b;
    Derived d1(b);
    std::cout << d1.text() << std::endl;

    Derived d2(d1);
    std::cout << d2.text() << std::endl;
    return 0;
}

并输出:

Base …

我有2张桌子:user和post.

使用show create table语句:

CREATE TABLE `user` (
  `user_id` bigint(20) NOT NULL AUTO_INCREMENT,
  `user_name` varchar(20) CHARACTER SET latin1 NOT NULL,
  `create_date` datetime DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB AUTO_INCREMENT=59 DEFAULT CHARSET=utf8;

CREATE TABLE `post` (
  `post_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `owner_id` bigint(20) NOT NULL,
  `data` varchar(300) CHARACTER SET latin1 DEFAULT NULL,
  PRIMARY KEY (`post_id`),
  KEY `my_fk` (`owner_id`),
  CONSTRAINT `my_fk` FOREIGN KEY (`owner_id`) REFERENCES `user` (`user_id`) ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=1012919 DEFAULT CHARSET=utf8;

一切都很好我用ORDER …