mptt refers to "Modified Preorder Tree Traversal" algorithm for storing hierarchical data
mptt refers to "Modified Preorder Tree Traversal" algorithm for storing hierarchical data.
See also:
Questions tagged [mptt]
146 questions
0
votes
1 answer
Is it possible to rebuild a single tree?
I can only find documentation for Model.objects.rebuild() which rebuilds all trees.
What if I wanted to rebuild a single tree? Is that possible?
If it's not possible - does that mean using move_node or insert_node results in rebuilding for all…
Chris
- 500
- 6
- 25
0
votes
1 answer
Fully mapping out object of unknown "depth" (and the most efficient way of finding the "depth" of an object)
I have a "parent" object that has an unknown "depth" of children.
My ultimate goal is to be able to fully map this "parent" object of unknown depth with all its levels of children - how would I do this?
Each child already has its "depth" associated…
Chris
- 500
- 6
- 25
0
votes
1 answer
TreeNodeChoiceField not iterable in a form - Django
I was wondering if someone was familiar with TreeNodeChoiceField from mptt in Django. I am trying to use this feature in a form to post an article on a blog. But when I try to create a new post it says that the object associated is not iterable.…
Alain Turner
- 25
- 5
0
votes
1 answer
python - mptt for nested lists
I have read a little about mptt solution and I'm trying to implement some sort of translating a nested list into a mptt list. I know, that in this format it's useless, but nested lists can be easily changed with a classes childs or anything…
Gandi
- 3,522
- 2
- 21
- 31
0
votes
1 answer
How to limit the max deep of recursetree in Django mttp?
I'm using django-mttp. How can I limit the max depth of recursetree? Max=3
Model:
class Comment(MPTTModel):
"""评论表"""
nid = models.AutoField(primary_key=True)
news = models.ForeignKey(
verbose_name="评论文章",
to="News",
…
William
- 3,724
- 9
- 43
- 76
0
votes
1 answer
Django mptt, can I delete the default 'name' filed?
I'm following the django-mptt tutorial,and there is a 'name' filed:
class Genre(MPTTModel):
name = models.CharField(max_length=50, unique=True)
parent = TreeForeignKey('self', on_delete=models.CASCADE, null=True, blank=True,…
William
- 3,724
- 9
- 43
- 76
0
votes
1 answer
Return a reference of an object instance
I'm working on a MPTT object that will support several database methods. First of is MySQL and MySQLi. Now I've created it like this
Mptt - The main object that will load the correct sub object
class Mptt {
/**
* Array of available driver types
*…
Ole Aass
- 173
- 1
- 4
0
votes
1 answer
django-mptt and ForeignKey with blank=True
I am using django-mptt in my project
models.py:
class Category(models.Model):
name = models.TextField()
parent = models.ForeignKey("self", blank=True, null=True,
related_name="sub_category")
image =…
Eugene Nagorny
- 1,626
- 3
- 18
- 32
0
votes
1 answer
Failed lookup for key [category] in [{'True': True, 'False': False, 'None': None}, {}, {},
I'm getting this error Failed lookup for key [category] in [{'True': True, 'False': False, 'None': None}, {}, {}, ....]
in my application I have category and subcategory which repeated too much in my view for every function and for child or…
Shir Danishyar
- 11
- 4
0
votes
1 answer
MySQL, PHP, MPTT: Sort children on weight/cost/menu_order
SELECT node . * , node.page_id, (COUNT( parent.page_id ) - ( sub_tree.depth +1 )) AS depth
FROM pages AS node, pages AS parent, pages AS sub_parent, (
SELECT node.page_id, (
COUNT( parent.page_id ) -1
) AS depth
FROM pages AS node,…
0
votes
1 answer
How to set post_id to resolve error : 'django.db.utils.IntegrityError: NOT NULL constraint failed: posts_comment.post_id'?
I am using Django and attempting to add commenting functionality with AJAX. When I click on the submit button for the comment, the action is not being performed and I am instead seeing a 'django.db.utils.IntegrityError: NOT NULL constraint failed:…
Ahmed Yasin
- 886
- 1
- 7
- 31
0
votes
1 answer
I cannot create category and sub-categories list in home page,django
I can create a category page with sub-categories in a new template but i cannot list all my sub-categories in home page. All i need is a logic to work in home page.
Here is my models.py
class Category(MPTTModel):
name =…
0
votes
1 answer
Outputting all value descendants from a table when ManyToMany Django ORM
There are two tables
catalog_product:
id |name
10 prod3
9 prod2
8 prod1
11 prod5
catalog_productcategory: (mptt model)
id | name | lft | rght | tree_id | level | parent_id
2 root1 1 6 1 0 null
3…
Андрей Иванов
- 101
- 1
0
votes
1 answer
How to include dropdown menu with django-mptt in template
I want to be able to create dropdown menu using admin panel. At this moment in model I can choose if subpage is children of another and in what order it should be displayed. But I don't know how to implement all of this together in template. Can…
dawhry
- 17
- 5
0
votes
1 answer
What is the most efficient way to query a MPTT style table by path?
I have a MySQL table that stores hierarchical data using the MPTT method. The table also has a column in which I store a short string identifier (slug) for each row.
I'd like to be able to query the table to find the correct row when given a path…
Mark Perkins
- 260
- 2
- 10