Is there anyway to use retract in Swish?

Help!
1

If hit the snag of No permission to call sandboxed `retract(_1684)’ when trying to translate an SQL delete example in my Swish database tutorial.

Is there some magic incantation to allow facts to be removed from the database in Swish?

2

retract/1 works fine, but the argument needs to be a sufficiently instantiated term. If not, it can be a module qualified term and retract things outside the sandbox. So you get something like

forall(member(p(X), Terms), retract(p(X))).
1 Like
3

Many thanks for the prompt response as always @jan

For those who need a fuller explanation, this works:

forall(member(student(SID, SName, GPA, SizeHS), Students), 
           retract(student(SID, SName, GPA, SizeHS))).

I originally wrote forall(member(Student, Students), retract(Student)). which caused the error.