Added helper functions to generate SQL that works on multiple databases
Added helper functions to generate SQL that works on multiple databases

skirsdeda/django-treebeard,skirsdeda/django-treebeard,django-treebeard/django-treebeard,tabo/django-treebeard,tabo/django-treebeard,tabo/django-treebeard,skirsdeda/django-treebeard,django-treebeard/django-treebeard,tabo/django-treebeard,skirsdeda/django-treebeard,django-treebeard/django-treebeard