安装pymssql出现的错误：如下：

----------------------------------------

  Failed building wheel for pymssql
  Running setup.py clean for pymssql
Failed to build pymssql
Installing collected packages: pymssql
  Running setup.py install for pymssql ... error
    Complete output from command /usr/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-d11b_9n3/pymssql/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-x8ogg8xp-record/install-record.txt --single-version-externally-managed --compile --user --prefix=:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-d11b_9n3/pymssql/setup.py", line 88, in <module>
        from Cython.Distutils import build_ext as _build_ext
    ModuleNotFoundError: No module named 'Cython'
    
    ----------------------------------------

Command "/usr/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-d11b_9n3/pymssql/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-x8ogg8xp-record/install-record.txt --single-version-externally-managed --compile --user --prefix=" failed with error code 1 in /tmp/pip-build-d11b_9n3/pymssql/

解决方法：

命令：export PYMSSQL_BUILD_WITH_BUNDLED_FREETDS=1

命令：pip3 install pymssql