Thread: C++ and mysql. I'm getting an error i dont understand.

hi,
i'm trying to interface with a mysql db from C++ and I'm getting weird compilation errors. i'm running Slackware7.0.

this is the program:

Code:

#include <mysql/mysql.h>
#include <stdio.h>

#define host "127.0.0.1"
#define username "root"
#define password ""
#define db "ccnums"



int main()
{
	MYSQL *conn;
	conn = mysql_init(NULL);
	mysql_real_connect(conn, host, username, password, db, 0, NULL, 0);
	
	MYSQL_RES *res_set;
	MYSQL_ROW row;
	unsigned int i;
	
	mysql_query(conn, "select * from nums");
	res_set = mysql_store_result(conn);
	
	unsigned int numrows = mysql_num_rows(res_set);
	while((row = mysql_fetch_row(res_set)) != NULL) 
	{
		for (i=0; i<mysql_num_fields(res_set); i++)
			printf("%s\n", row[i] != NULL ? row[i] : "NULL");
	}
	
	mysql_close(conn);
	return 0;
}

and the errors:

Code:

/tmp/ccVA60Wf.o: In function `main':
/tmp/ccVA60Wf.o(.text+0xc): undefined reference to `mysql_init'
/tmp/ccVA60Wf.o(.text+0x37): undefined reference to `mysql_real_connect'
/tmp/ccVA60Wf.o(.text+0x4b): undefined reference to `mysql_query'
/tmp/ccVA60Wf.o(.text+0x5a): undefined reference to `mysql_store_result'
/tmp/ccVA60Wf.o(.text+0x6e): undefined reference to `mysql_num_rows'
/tmp/ccVA60Wf.o(.text+0x88): undefined reference to `mysql_fetch_row'
/tmp/ccVA60Wf.o(.text+0xaf): undefined reference to `mysql_num_fields'
/tmp/ccVA60Wf.o(.text+0x10d): undefined reference to `mysql_close'
collect2: ld returned 1 exit status

i'd appreciate it if someone would clear this up for me.

Martin

I'm using Mandrake 8.2 and get the same message!
Very frustrating.
I also looking for some help about this
Anyone?

I tried this:

$ gcc main.c -l/usr/local/mysql/include/mysql -L/usr/local/mysql/lib/libmysqlclient -o connect1

and I get this:

/usr/bin/ld: cannot find -l/usr/local/mysql/include/mysql
collect2: ld returned 1 exit status

So exactly what do I have to do?

Thanks Salem. I'm very thanks full.
I'm not sure that the new error that apears
is in this case, but anyway here they are:

/usr/local/mysql/lib//libmysqlclient.a(my_compress.o): In function `my_uncompress':
my_compress.o(.text+0xa2): undefined reference to `uncompress'
/usr/local/mysql/lib//libmysqlclient.a(my_compress.o): In function `my_compress_alloc':
my_compress.o(.text+0x13a): undefined reference to `compress'
collect2: ld returned 1 exit status

Any suggestions?

Hi again
I have to tell that I get a solution for the last problem.
I have to add -lz to the command.
That has the gcc locking in the right library for the 'compress'

Now I'm happy again.