Take a look at this… awesome!

This picture was generated from data collected from plain text logfiles inserted into MySQL using Perl, queried using Python/SQLAlchemy, served using a Python/WSGI application through SCGI using flup and Apache2 and plotted using JavaScript on Mozilla Firefox… and I get paid to do that!

gcc -fno-strict-aliasing -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -fPIC -Dversion_info=(1,2,3,'gamma',1) -D__version__=1.2.3c1 -I/opt/mysql/mysql/include -I/opt/alcatel/logger/include/python2.6 -c _mysql.c -o build/temp.solaris-2.10-sun4u-2.6/_mysql.o -g -mt -m32 -xarch=sparc -DHAVE_RWLOCK_T -DUNIV_SOLARIS -DUNIV_SOLARIS
gcc: warning: `-x arch=sparc' after last input file has no effect
cc1: error: invalid option `t'
error: command 'gcc' failed with exit status 1

It happened to me on a Sun Fire V240 (sparc), but may also happen on i386.

The problem here is the “-mt” option. As mentioned in this forum post the “-mt” option is targeted at IA-64 platforms. This option is used because it is also used in MySQLs “–cflags” and setup.py uses mysql_config to determine build options. If you run mysql_config you probably get something like this:

# /opt/mysql/mysql/bin/mysql_config --cflags
-I/opt/mysql/mysql/include  -g -mt -m32 -xarch=sparc   -DHAVE_RWLOCK_T -DUNIV_SOLARIS -DUNIV_SOLARIS

To overcome this I added “m” to the compiler options to ignore in setup_posix.py in line 55:

removable_compile_args = [ compiler_flag(f) for f in "ILlm" ]

This makes it not use the “-mt -m32″ options from mysql_config. The “-m32″ option makes gcc generate code for 32-bit systems and regarding the “-x arch=sparc”: gcc ignores it anyway:

gcc: warning: `-x arch=sparc' after last input file has no effect

Furthermore there is a bug in the setup.py that seems to link dynamically even if you configure it to link statically in site.cfg. There is a patch attached to this ticket.

Assuming an error like 1452 happened after a successful insert statement that inserted eg. 1 row. If you now use get_affected_rows_length, you still get 1 instead of 0. You should get 0, as the last executed query did affect 0 rows, because of a foreign key constraint.

The fix is easy — just set affected_rows_length to 0 in  _reset_status():

Index: Net/MySQL.pm
===================================================================
--- Net/MySQL.pm	(revision 1)
+++ Net/MySQL.pm	(working copy)
@@ -449,6 +449,7 @@
 	$self->{server_message}  = '';
 	$self->{error_code}      = undef;
 	$self->{selected_record} = undef;
+	$self->{affected_rows_length} = 0;
 }