code: def generic_find_constraint_name(table, columns, referenced, db):
      
      t = sa.Table(table, db.metadata, autoload=True, autoload_with=db.engine)
  
      for fk in t.foreign_key_constraints:
          if fk.referred_table.name == referenced and set(fk.column_keys) == columns:
              return fk.name
docs: Utility to find a constraint name in alembic migrations