what is lft and rgt?

[Sina miandashti]

hi everyone...


what is lft and rgt exactly ?

we saw them in q_information_object table ... and we findout that if
their number change it makes the context fond menu not showing ....


what are they exactly ? and what are their numbers means ?

for example for information object id 138 the lft and rgt is 3 &
16 ! what is it means ?


regards


Sina, Member of National Archives of Iran

[David Juhasz]

Hi Sina,

The "lft" and "rgt" columns are used for the "Nested Set Model" for managing hierarchical data.  You can read more here:
http://dev.mysql.com/tech-resources/articles/hierarchical-data.html
(Sorry, I don't know if there is a version in Farsi).

There is some more detail about how we are using the nested set model in Qubit/ICA-AtoM here:
http://qubit-toolkit.org/index.php?title=Developing_and_Contributing_Code#Hierarchy

I hope that helps!

Regards,

David Juhasz Software Engineer - Artefactual Systems Inc. tel: 604.527.2056, fax: 604.521.2059

[Sina miandashti]

hi

thanks a lot mate.

i make a lot of fonds and sub fonds by this ;)

thanks ... u soved our problem.



Regards

Sina , M
Member of National Archives of Iran.