我没有得到错误，而安装宝石ruby-odbc -v '0.99995'。请帮助我解决这个错误。我尝试了很多东西，但它没有工作。

Building native extensions.  This could take a while...
ERROR:  Error installing ruby-odbc:
    ERROR: Failed to build gem native extension.
/home/sheetal/.rvm/rubies/ruby-1.8.7-p371/bin/ruby extconf.rb
checking for version.h... yes
checking for sql.h... no
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.
Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
    --without-make-prog
    --srcdir=.
    --curdir
    --ruby=/home/sheetal/.rvm/rubies/ruby-1.8.7-p371/bin/ruby
    --with-odbc-dir
    --without-odbc-dir
    --with-odbc-include
    --without-odbc-include=${odbc-dir}/include
    --with-odbc-lib
    --without-odbc-lib=${odbc-dir}/lib
ERROR: sql.h not found

字符串
我使用的是Ruby 1.8.7和Rails 2