导入pymssql时出错

Question

I am trying to import pymssql and I am getting this error (I think I have installed it correctly):

Traceback (most recent call last):
File "sql.py", line 1, in <module>
    import pymssql
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pymssql.so, 2): Symbol not found: _dbversion
  Referenced from: /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pymssql.so
  Expected in: dynamic lookup

How do I solve this?

Answer 1

The symbol was not found on import, possibly due to a linking problem at compilation when setup.py was run.

I ran into this particular issue because I was running 32-bit Python 2.7.12 on my OS X machine. Doing the following resolved the issue for me:

• Making sure I had the right version of FreeTDS installed. Until pymssql 2.20 is released, pymssql is not compatible with FreeTDS 1.0 . You can install FreeTDS 0.91 on OS X with brew uninstall freetds and brew install homebrew/versions/freetds091
• Making sure I had the 64-bit version of Python 2.7.12 installed. This a quick way to verify if you're running python as 32 or 64 bit . I used the python.org installer instead of using brew install python
• Making sure I wasn't relying on a pip cache when installing pymssql. Instead, I used pip install --no-cache-dir pymssql

You need FreeTDS for the build to succeed, and if you don't build with the proper architecture, it is possible you will run into this error.

Hope this helps!