Hi @Anonymous ,
@Edrei did a great job identifying how to fix this...
I would like to suggest something if you may... I usually avoid N:N relationships because it does not allow me to create attributes that define this relationship.
As an example with Physicians and Hospitals you might want to define attributes about this relationship (i.e. dates, role, primary nurse, etc.).
I would normally create a table in-between these two tables and use 1:N relationships in-between. You can then really do a lot more with these and define fields, other relationships from this table etc. Structure would be something like:
Hospital ---1:N---> Hospital Physician <---N:1---Physician
Just thought I would mention this because most times i have ever gone down the N:N path I have switched to this.
Hope this helps. Please accept if answers your question and Like if helps in any way.
Thanks,
Drew