MySQL_Query使用C ++ [英] MySQL_Query With C++
问题描述
大家好，
我正在寻找如何从数据库（MySQL）中提取数据并将其分配到我的程序中的变量中。这里有一些代码可以举例说明我的意思。
I'm finding out how to extract data out from database(MySQL) and assign it into a variable in my program. Here are some codes to give an example of what i meant.
MYSQL_RES * filter_exp;
MYSQL_RES *filter_exp;
MYSQL * conn; //指向MySQL结构的指针
MYSQL *conn; // pointer to MySQL structure
conn = mysql_init（NULL）; //连接句柄
conn = mysql_init(NULL); // connection handle
//连接MySQL数据库
// Connect to MySQL database
//主机地址= localhost，用户名= root，数据库=项目
// host address = localhost, username = root, database = project
mysql_real_connect（conn，"localhost"，" root"，""，""project"，0，NULL，0）;
mysql_real_connect(conn, "localhost", "root", "", "project", 0, NULL, 0);
MYSQL_RES * res_set; / *创建一个指针来接收返回值。*
MYSQL_RES *res_set; /* Create a pointer to recieve the return value.*
mysql_query（conn，"SELECT Filter FROM setting"）; / *向数据库发送查询。 * /
mysql_query(conn,"SELECT Filter FROM setting"); /* Send a query to the database. */
filter_exp = mysql_store_result（conn）; / *收到结果并将其存储在res_set * /
filter_exp = mysql_store_result(conn); /* Receive the result and store it in res_set */
;
但是，它仍有错误。在我的代码的底部，有一大堆编码，其中声明了filter_exp。
But still, it has errors. At the bottom of my codes, there is this junk of codings where filter_exp is declared.
/ *
/*
*编译+设置过滤器
* Compiling + setting the filter
*
*
* /
*/
if（lDevice- >地址！= NULL）
if (lDevice->addresses != NULL)
      / *检索界面第一个地址的掩码* /
/* Retrieve the mask of the first address of the interface */
      net =（（struct sockaddr_in *）（lDevice-> addresses-> netmask）） - > sin_addr.S_un.S_addr;
net=((struct sockaddr_in *)(lDevice->addresses->netmask))->sin_addr.S_un.S_addr;
 否则
else
      / *如果界面没有地址，我们认为是在C类网络中* /
/* If the interface is without an address we suppose to be in a C class network */
      net = 0xffffff;
net=0xffffff;
if（pcap_compile（ lIFCHandle，& lFCode，filter_exp，0，net）== -1）{
if (pcap_compile(lIFCHandle, &lFCode, filter_exp, 0, net) == -1) {
fprintf（stderr ，"无法解析过滤器％s：％s \ n"，filter_exp，pcap_geterr（lIFCHandle））;
fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp, pcap_geterr(lIFCHandle));
; return（2）;
return(2);
}
if（pcap_setfilter（lIFCHandle，& lFCode）== -1）{
if (pcap_setfilter(lIFCHandle, &lFCode) == -1) {
fprintf（stderr，"无法安装过滤器％s：％s \ n"，filter_exp，pcap_geterr（lIFCHandle））;
fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, pcap_geterr(lIFCHandle));
return（2）;
return(2);
}
它给我一个错误。
ARGUMENT OF TYPE" MYSQL_RES *"与"CONST CHAR *"的参数不相容
ARGUMENT OF TYPE "MYSQL_RES *" IS INCOMPATIBLE WITH PARAMETER OF TYPE "CONST CHAR * "
我真的不知道发生了什么。
I don't really get what is going on.
推荐答案
您好LeRoyce，
Hi LeRoyce,
我建议您使用以下链接，其中包含示例程序并讨论如何访问MySQL数据库。
请参阅 他们有关更多有用信息：
http://www.codeproject.com/KB/ CPP / sdba.aspx 。本文讨论如何使用Visual C ++将图像上传到MySQL数据库：
http://www.codeproject.com/KB/database/mysqlimageimport.aspx 。
这是另一个在Visual C ++ General论坛中处理VC ++和MySQL的线程。请参阅它以获取更多有用的信息：
http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/c355f043-db6d-4d36-ae87-f9a4575be4b1 。
I recommend the following links for you, which contain sample routines and talk about how to access MySQL data base.
Please refer to them for more helpful information:
http://www.codeproject.com/KB/cpp/sdba.aspx. And this article discusses how to upload images to MySQL database using Visual C++:
http://www.codeproject.com/KB/database/mysqlimageimport.aspx.
And here is another thread which deals with VC++ and MySQL in Visual C++ General forum. Please refer to it for more helpful information:
http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/c355f043-db6d-4d36-ae87-f9a4575be4b1.
顺便说一句，MySQL不是微软的产品。如果您对MySQL有疑问，我建议您转到" MySQL论坛"。为了获得更有效的回复。
By the way, MySQL is not a product of Microsoft. If you have questions about MySQL, I suggest you move to "MySQL Forums" to get more efficient responses.
最好的问候，
海伦
Best regards,
Helen
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