小编Dan*_*vah的帖子

如何使用这2个连接来运行连接2个表的查询？yesno.table1和sushi.table1？让我们说我们加入id他们都有相同的ID.我怎样才能做到这一点？

// Connect to Yesno Database
$this->yesno_db = new mysqli("red", "yesno", "***", "yesnotmp");

if ($this->yesno_db->connect_errno) {
    throw new Exception('Connection failed: '.$this->yesno_db->connect_error);
}   

// Connect to Sushi Database
$this->sushi_db = new mysqli("red", "sushi", "***", "sushi");

if ($this->sushi_db->connect_errno) {
    throw new Exception('Connection failed: '.$this->sushi_db->connect_error);
}

我希望我的程序可以在不使用Microsoft Outlook或其他程序或SMTP服务器的情况下发送电子邮件.那可能吗？我是否可以在不连接SMTP服务器的情

是否有可能在mysql db中创建一个独特的2个coulmns？例如:

ID | columnA | columnB
 1 | Dan     | 1
 2 | Dan     | 2
 3 | Zak     | 1
 4 | Dan     | 1 (WHEN TRYING TO INSERT ROW 4 - NOT ALLOWED! DUPLICATE COULMNA + COLUMNB)

我正在尝试创建一个循环链表,并且我正在加载一些错误.当我试图从Node内部访问Employee结构时,看起来错误正在讨论derefencing指针.

这是我得到的错误:

 magic.c: In function ‘buildList’:
magic.c:49:2: error: dereferencing pointer to incomplete type
 n->e.id = 1;
  ^
magic.c:53:4: error: dereferencing pointer to incomplete type
   n->e = e;
    ^
magic.c:54:4: error: dereferencing pointer to incomplete type
   n->d = d; 
    ^
magic.c:55:8: error: dereferencing pointer to incomplete type
   n = n->next = (ptr)malloc(sizeof(node)); 
        ^
magic.c:58:3: error: dereferencing pointer to incomplete type
  n->next = head;
   ^
magic.c:58:12: error: ‘head’ undeclared (first use in this function)
  n->next = head;
            ^
magic.c:58:12: note: each undeclared …