MySQL with C++

[Royce Ho]

Hi Guys,

How do i get a value from the database and assign it to a variable using C++ language.

My program requires me to extract a value from the "setting" table, field=filter, get the value and assign it to

char filter_exp[] = ""; /* The filter expression */

The null value is actually what i query for in the "setting" table, field=filter.

Lets say for example TCP. It will actually assign TCP to that variable.

Please advice.


These are some codes from my program.

char filter_exp[] = ""; /* The filter expression */

MYSQL *conn; // pointer to MySQL structure

conn = mysql_init(NULL); // connection handle



// Connect to MySQL database
// host address = localhost, username = root, database = project
mysql_real_connect(conn, "localhost", "root", "", "project", 0, NULL, 0);
sprintf(cmd6, "DELETE FROM start");
mysql_real_query(conn, cmd6 , strlen(cmd6));


mysql_query(conn, "SELECT Filter from setting where transmit='1'");


-------------------------------------------------------------------------------

/*
* Compiling + setting the filter
*
*/


if (lDevice->addresses != NULL)
/* Retrieve the mask of the first address of the interface */
net=((struct sockaddr_in *)(lDevice->addresses->netmask))->sin_addr.S_un.S_addr;
else
/* If the interface is without an address we suppose to be in a C class network */
net=0xffffff;

if (pcap_compile(lIFCHandle, &lFCode, filter_exp, 0, net) == -1) {
fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp, pcap_geterr(lIFCHandle));
return(2);
}
if (pcap_setfilter(lIFCHandle, &lFCode) == -1) {
fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, pcap_geterr(lIFCHandle));
return(2);
}