can i install the mysql-server in my openwrt,how?

currently, only client binaries are provided for two reasons :  programs are usually linked agains the mysql client library, and the wrt has not the capacity to execute a mysql server, it may harm the flash and there is not enough space I believe, but if you want to try, why not

i already give up using the my-sol

I'm trying to compile the mysql client libs from bitbake files, and I keep hitting the error:

checking for atomic_add... configure: error: cannot run test program while cross compiling

Does anyone have an idea as to what the solution is?

Remove the test in the configure script. Usually it's something like that causing this kind of error :

 test "$cross_compiling" = yes &&
  { { echo "$as_me:$LINENO: error: cannot check for file existence when cross compiling" >&5
echo "$as_me: error: cannot check for file existence when cross compiling" >&2;}
   { (exit 1); exit 1; }; }
if test -r "$kernelpath/net/core/link_watch.c"; then
  eval "$as_ac_File=yes"
else
  eval "$as_ac_File=no"
fi

needs to be changed in :

 test "$cross_compiling" = yes &&
  { { echo "$as_me:$LINENO: error: cannot check for file existence when cross compiling" >&5
echo "$as_me: error: cannot check for file existence when cross compiling" >&2;} }
if test -r "$kernelpath/net/core/link_watch.c"; then
  eval "$as_ac_File=yes"
else
  eval "$as_ac_File=no"
fi
fi

MySQL client library is already in CVS. Look at the patches subfolder and try to apply the 500-cross-compile.patch patch.

The client library you want to use seems bundled with the source you're trying to build. You'd better try to link with the already built libmysqlclient.so found in the STAGING_DIR directory to avoid wasting more space.