The answer is yes, with qualifications and warnings
If you are planning to simply read information from the GP tables, then you should not run into any problems.
If you are planning to create/update transactions then although possible to directly interact with the GP tables, I (and many others) would not recommend it. Although you may think you are saving money by not purchasing eConnect, you will need to make sure your code/script makes the exact same table changes as the eConnect business logic otherwise you will finish up corrupting the data.
Regards
Andrew Dean
