[Bug]: spec.get() error

[longbingljw]

Describe the bug

When I use ob as vector db to create document indexs in dify,"'str' object has no attribute 'get' " occured.The error occurs in the reflection.py file of the pyobvector library, where the spec variable is a string instead of a dictionary in certain cases, but the code directly calls spec.get().

Environment

pyobvector 0.2.14 latest

Fast reproduce steps

When using ob as vector db to create document indexs in dify,"'str' object has no attribute 'get' " occured.

Expected behavior

No response

Actual behavior

worker-1 | File "/app/api/.venv/lib/python3.12/site-packages/pyobvector/schema/reflection.py", line 79, in _par
se_constraints
worker-1 | if spec.get("onupdate", "").lower() == "restrict":
worker-1 | ^^^^^^^^
worker-1 | AttributeError: 'str' object has no attribute 'get'

Additional context

'str' object has no attribute 'get'

[longbingljw]

It's roughly like this: pyobvector uses the SQLAlchemy MySQL dialect, but in cases where parsing fails, it returns a string type. However, pyobvector doesn't check and assumes that spec will only be of dict type, so it crashes when calling .get(). The fix should add a type check.