Hibernate 6 equivelant of SQLFunction render

I am struggling to find out how to migrate my code containing org.hibernate.dialect.function.SQLFunction.render method … to Hibernate 6

SessionFactoryImplementor d = this.entityManagerFactory.unwrap(SessionFactoryImplementor.class);
        SQLFunction fnc = d.getSqlFunctionRegistry()
                .findSQLFunction("fncName“);

String render = fnc.render(null, expressions,
                this.entityManagerFactory.unwrap(SessionFactoryImplementor.class));

the first part I guess should be

SqlFunction fnc = (SqlFunction) d.getQueryEngine().getSqmFunctionRegistry().findFunctionDescriptor("fncName“);

but I am stuck with the the 2nd part

Solution

SessionFactoryImplementor is documented as an SPI, and so we don't really recommend using it in this way.

/**
 * Defines the internal contract between the {@link SessionFactory} and the internal
 * implementation of Hibernate.

At least, if you do this sort of thing, you do it at your own risk.

As you've noticed, SqmFunctionDescriptor, which is the replacement for SQLFunction, is a much more technical API, which was a very necessary change, because Hibernate's handling of functions is now much more sophisticated.

I can't really imagine why you would want to be hand-rendering a function invocation, but I'm sure you must have your reasons. Whatever they are, I think it's not likely to work, at least not without an unreasonable amount of messiness.

Sorry.