小编ars*_*ium的帖子

我在这里看到许多使用NOT NULL约束创建表的示例。具有讽刺意味的是，我似乎无法做到这一点。

这是我使用的cql命令：

CREATE TABLE activities_dev (activity_id  uuid ,actor_id bigint NOT NULL, actor_appid bigint NOT NULL, item_id text NOT NULL, verb text NOT NULL,viewer_id bigint NOT NULL,viewer_appid bigint NOT NULL, ts timestamp, PRIMARY KEY(activity_id,actor_id,actor_appid,item_id,verb));

但这是我得到的错误：

SyntaxException: line 1:62 mismatched input 'NOT' expecting ')' (...activities_dev(activity_id uuid, actor_id integer [NOT] NULL...)

我究竟做错了什么 ？

#include <iostream>
#include <memory>
class Member {
public:
  Member() {
    std::cout << "Member::ctor" << std::endl;
    throw "Exception";
  }
  ~Member() {
    std::cout << "Member::dtor" << std::endl;
  }
};
class Base {
public:
  Base() {
    std::cout << "Base::ctor" << std::endl;
  }
  virtual ~Base() {
    std::cout << "Base::dtor" << std::endl;
  }
};

class Derived : public Base {
  Member* m_;
  public:
    Derived() : m_(new Member()) {
      std::cout << "Derived::ctor" << std::endl;
    }
  ~Derived() {
    if(m_) delete m_;
      std::cout << "Derived::dtor" << std::endl;
    } …