LOOK AT THE CODE ATTACHED:

I REMOVE COMPLETETY THE MANY TO MANY RELATIONS FROM HISTORY AS IT IS UNNECESSARY IF YOU SPECIFY THE TABLE THAT HOLD THAT RELATION AND ALSO DEFINE THE HISTORY TABLE FOR THAT.

I CONNECT THE FOREIGN KEY FROM HISTORY TABLE TO THE RELATED HISTORY TABLE

WE NEED TO CONNECT TO POST_SAVE SIGNAL IN ORDER TO HAVE IN HISTORY ALL DATA AND CATCHING THE DELETE SIGNAL IS NOT NECESSARY.

ALSO IF USING A DATABASE THAT DOES NOT IMPLEMENT SERIAL DATA TYPE (AS SQLITE3) THE HISTORY WON'T LOOK GOOD.

As far as a test this code works good.

Cristian scristian71@yahoo.com