Comment 1 for bug 291374

I have the same problem (ulogd.c... load_plugins... ulogd_MYSQL.so... undefined symbol: mysql_fetch_field).

Ubuntu source package contains a patch specific to Ubuntu about the MySQL module:
--------------------------- 8< ------------------------
--- ulogd-1.24/mysql/Makefile.in 2005-11-25 20:58:27.000000000 +0100
(...)
 SHARED_LIBS=ulogd_MYSQL.so

+# fix the LDFLAGS included in MYSQL_LDFLAGS
+MYSQL_LDFLAGS:=$(shell echo $(MYSQL_LDFLAGS) | sed s/-Wl,//;s/-rpath//)
+

(...)
--------------------------- 8< ------------------------

First remark: I don't understand how the sed can work because ";" is the separator for shell commands. It should be >sed 's/-Wl,//;s/-rpath//'<.

The command "mysql_config --libs" creates arguments for gcc, not for ld program:
--------------------------- 8< ------------------------
$ mysql_config --libs
-Wl,-Bsymbolic-functions -rdynamic -L/usr/lib/mysql -lmysqlclient
--------------------------- 8< ------------------------

It looks like -rdynamic causes a link problem (bad -rpath option).

I don't know ld/gcc/dlopen options very well, but I'm sure that ulogd_MYSQL.so have to linked to libmysqlclient.so.15. Example on Ubuntu Ibex :
$ ldd /usr/lib/ulogd/ulogd_MYSQL.so
 linux-gate.so.1 => (0xb7f48000)
 libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7dd5000)
 /lib/ld-linux.so.2 (0xb7f49000)

Example on Debian Lenny:
$ ldd /usr/lib/ulogd/ulogd_MYSQL.so
 linux-gate.so.1 => (0xb7f98000)
 libmysqlclient.so.15 => /usr/lib/libmysqlclient.so.15 (0xb7db4000)

The bug is still open since 3 months, why? Do you need more informations? The package is compiled correctly on Debian.