It's possible a user could provide a non-unique user identifier for a session via custom sql, this ensures we take the max as we do with non-custom sql
Checklist
[x] I have verified that these changes work locally
[ ] I have updated the README.md (if applicable)
[ ] I have added tests & descriptions to my models (and macros if applicable)
Description & motivation
It's possible a user could provide a non-unique user identifier for a session via custom sql, this ensures we take the max as we do with non-custom sql
Checklist