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https://github.com/uralbash/sqlalchemy_mptt

SQLAlchemy nested sets mixin (MPTT)
https://github.com/uralbash/sqlalchemy_mptt

mptt nested-set python sqlalchemy

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SQLAlchemy nested sets mixin (MPTT)

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README

        

|Build Status| |Coverage Status|

Library for implementing Modified Preorder Tree Traversal with your
SQLAlchemy Models and working with trees of Model instances, like
django-mptt. Docs http://sqlalchemy-mptt.readthedocs.io/

.. image:: https://cdn.rawgit.com/uralbash/sqlalchemy_mptt/master/docs/img/2_sqlalchemy_mptt_traversal.svg
:alt: Nested sets traversal
:width: 800px

The nested set model is a particular technique for representing nested
sets (also known as trees or hierarchies) in relational databases.

Installing
----------

Install from github:

.. code-block:: bash

pip install git+http://github.com/uralbash/sqlalchemy_mptt.git

PyPi:

.. code-block:: bash

pip install sqlalchemy_mptt

Source:

.. code-block:: bash

pip install -e .

Usage
-----

Add mixin to model

.. code-block:: python

from sqlalchemy import Column, Integer, Boolean
from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy_mptt.mixins import BaseNestedSets

Base = declarative_base()

class Tree(Base, BaseNestedSets):
__tablename__ = "tree"

id = Column(Integer, primary_key=True)
visible = Column(Boolean)

def __repr__(self):
return "" % self.id

Now you can add, move and delete obj!

Insert node
-----------

.. code-block:: python

node = Tree(parent_id=6)
session.add(node)

::

level Nested sets example
1 1(1)22
_______________|___________________
| | |
2 2(2)5 6(4)11 12(7)21
| ^ ^
3 3(3)4 7(5)8 9(6)10 13(8)16 17(10)20
| |
4 14(9)15 18(11)19

level Insert node with parent_id == 6
1 1(1)24
_______________|_________________
| | |
2 2(2)5 6(4)13 14(7)23
| ____|____ ___|____
| | | | |
3 3(3)4 7(5)8 9(6)12 15(8)18 19(10)22
| | |
4 10(23)11 16(9)17 20(11)21

Delete node
-----------

.. code:: python

node = session.query(Tree).filter(Tree.id == 4).one()
session.delete(node)

::

level Nested sets example
1 1(1)22
_______________|___________________
| | |
2 2(2)5 6(4)11 12(7)21
| ^ ^
3 3(3)4 7(5)8 9(6)10 13(8)16 17(10)20
| |
4 14(9)15 18(11)19

level Delete node == 4
1 1(1)16
_______________|_____
| |
2 2(2)5 6(7)15
| ^
3 3(3)4 7(8)10 11(10)14
| |
4 8(9)9 12(11)13

Update node
-----------

.. code:: python

node = session.query(Tree).filter(Tree.id == 8).one()
node.parent_id = 5
session.add(node)

::

level Nested sets example
1 1(1)22
_______________|___________________
| | |
2 2(2)5 6(4)11 12(7)21
| ^ ^
3 3(3)4 7(5)8 9(6)10 13(8)16 17(10)20
| |
4 14(9)15 18(11)19

level Move 8 - > 5
1 1(1)22
_______________|__________________
| | |
2 2(2)5 6(4)15 16(7)21
| ^ |
3 3(3)4 7(5)12 13(6)14 17(10)20
| |
4 8(8)11 18(11)19
|
5 9(9)10

Move node (support multitree)
-----------------------------

.. figure:: https://cdn.rawgit.com/uralbash/sqlalchemy_mptt/master/docs/img/3_sqlalchemy_mptt_multitree.svg
:alt: Nested sets multitree
:width: 600px

Nested sets multitree

Move inside

.. code:: python

node = session.query(Tree).filter(Tree.id == 4).one()
node.move_inside("15")

::

4 -> 15
level Nested sets tree1
1 1(1)16
_______________|_____________________
| |
2 2(2)5 6(7)15
| ^
3 3(3)4 7(8)10 11(10)14
| |
4 8(9)9 12(11)13

level Nested sets tree2
1 1(12)28
________________|_______________________
| | |
2 2(13)5 6(15)17 18(18)27
| ^ ^
3 3(14)4 7(4)12 13(16)14 15(17)16 19(19)22 23(21)26
^ | |
4 8(5)9 10(6)11 20(20)21 24(22)25

Move after

.. code:: python

node = session.query(Tree).filter(Tree.id == 8).one()
node.move_after("5")

::

level Nested sets example
1 1(1)22
_______________|___________________
| | |
2 2(2)5 6(4)11 12(7)21
| ^ ^
3 3(3)4 7(5)8 9(6)10 13(8)16 17(10)20
| |
4 14(9)15 18(11)19

level Move 8 after 5
1 1(1)22
_______________|__________________
| | |
2 2(2)5 6(4)15 16(7)21
| ^ |
3 3(3)4 7(5)8 9(8)12 13(6)14 17(10)20
| |
4 10(9)11 18(11)19

Move to top level

.. code:: python

node = session.query(Tree).filter(Tree.id == 15).one()
node.move_after("1")

::

level tree_id = 1
1 1(1)22
_______________|___________________
| | |
2 2(2)5 6(4)11 12(7)21
| ^ ^
3 3(3)4 7(5)8 9(6)10 13(8)16 17(10)20
| |
4 14(9)15 18(11)19

level tree_id = 2
1 1(15)6
^
2 2(16)3 4(17)5

level tree_id = 3
1 1(12)16
_______________|
| |
2 2(13)5 6(18)15
| ^
3 3(14)4 7(19)10 11(21)14
| |
4 8(20)9 12(22)13

Support and Development
=======================

To report bugs, use the `issue tracker
`_.

We welcome any contribution: suggestions, ideas, commits with new
futures, bug fixes, refactoring, docs, tests, translations, etc...

If you have question, contact me [email protected] or #sacrud IRC
channel |IRC Freenode|

License
=======

The project is licensed under the MIT license.

.. |Build Status| image:: https://travis-ci.org/uralbash/sqlalchemy_mptt.svg?branch=master
:target: https://travis-ci.org/uralbash/sqlalchemy_mptt
.. |Coverage Status| image:: https://coveralls.io/repos/uralbash/sqlalchemy_mptt/badge.png
:target: https://coveralls.io/r/uralbash/sqlalchemy_mptt
.. |IRC Freenode| image:: https://img.shields.io/badge/irc-freenode-blue.svg
:target: https://webchat.freenode.net/?channels=sacrud