When linking with the C API, the following errors may occur on some systems:

gcc -g -o client test.o -L/usr/local/lib/mysql \
                        -lmysqlclient -lsocket -lnsl

Undefined        first referenced
 symbol          in file
floor            /usr/local/lib/mysql/libmysqlclient.a(password.o)
ld: fatal: Symbol referencing errors. No output written to client

If this happens on your system, you must include the math library by adding -lm to the end of the compile/link line.

Linking with the single-threaded library (libmysqlclient) may lead to linker errors related to pthread symbols. When using the single-threaded library, please compile your client with MYSQL_CLIENT_NO_THREADS defined. This can be done on the command line by using the -D option to the compiler, or in your source code before including the MySQL header files. This define should not be used when building for use with the thread-safe client library (libmysqlclient_r).