MySQL Nested Datasets #JDNL13

NESTED DATA SETS
(THINK ACL)
JOOMLADAY NETHERLANDS 2013 - ELI ASCHKENASY - @ELIASCHKENASY 1

INTRODUCTION
 Eli Aschkenasy
 themodularway.com
 Oracle certified (doesn’t really mean anything)
 GE sourcing database project
 Agenda

AGENDA
 Introduction (5min)
 Simple Explanation of Nested Data Sets (10min)
 Types of Hierarchies (5min)
 The Joomla Way (5min)
 Basic Functions (15min)
 Advanced Functions (10min)
 The Ten Commandments (for ever…)

WELCOME TO OUR DEMO TEAM (COURTESY OF MS POWERPOINT TEMPLATES)
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash

NESTED SETS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash

NESTED SETS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
lft, rgt

NESTED SETS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
CEO
VP
Financial Support Marketing Sales Developme
nt
Research
position

NESTED SETS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
container

AGENDA

TYPES OF HIERARCHIES
Static nodes and static edges
 A chart of accounts in an accounting system will
probably not change much over time.
 This is probably best done with a hierarchical
encoding scheme rather than a table.
Static nodes and dynamic edges
 For example, an Internet Newsgroup message
board. Obviously you cannot add a node to a
tree without adding an edge, but the content of
the messages (nodes) never change once they
are posted; however, new replies can be posted
as subordinates to any existing message (edge).

Dynamic nodes and static edges
 This is the classic organizational chart in which
the organization stays the same, but the people
holding the offices rotate frequently.
 This is assuming that your company does not
reorganize more often than its personnel turns
over.
Dynamic nodes and dynamic edges
 The fastest path from the fire station to a
particular home address will not necessarily be
the same route at 5:00 AM as it will be at 5:00
PM.
 Once the fire is put out, the node that
represented the burning house can disappear
from the tree and the next fire location becomes
a to which we must find a path.

Dynamic nodes and static edges
 This is the classic organizational chart in which
the organization stays the same, but the people
holding the offices rotate frequently.
 This is assuming that your company does not
reorganize more often than its personnel turns
over.
Dynamic nodes and dynamic edges
 The fastest path from the fire station to a
particular home address will not necessarily be
the same route at 05:00 Hrs. as it will be at 17:00
Hrs.
 Once the fire is put out, the node that
represented the burning house can disappear
from the tree and the next fire location becomes
a to which we must find a path.

AGENDA

THE JOOMLA WAY - JTableNested
 http://docs.joomla.org/Using_nested_sets
 Table creation (required fields)
CREATE TABLE IF NOT EXISTS `#__nestedsets` (
ìd` int(11) NOT NULL AUTO_INCREMENT,
`parent_id` int(10) UNSIGNED NOT NULL DEFAULT '0',
`lft` int(11) NOT NULL DEFAULT '0',
`rgt` int(11) NOT NULL DEFAULT '0',
`level` int(10) UNSIGNED NOT NULL DEFAULT '0',
`title` varchar(255) NOT NULL,
àlias` varchar(255) NOT NULL DEFAULT '',
àccess` tinyint(3) UNSIGNED NOT NULL DEFAULT '0',
`path` varchar(255) NOT NULL DEFAULT '',
PRIMARY KEY (ìd`),
KEY ìdx_left_right` (`lft`,`rgt`)
) DEFAULT CHARSET=utf8;

 Creating Root Node
$sql = 'INSERT INTO ckm_profiles'
. ' SET parent_id = 0'
. ', lft = 0'
. ', rgt = 1'
. ', level = 0'
. ', title = '.$db->quote( 'root' )
. ', alias = '.$db->quote( 'root' )
. ', access = 1'
. ', path = '.$db->quote( '' )
;

 Basic Functions: getRootId() and update data (just like JTable)
$rootId = $table->getRootId();
if ($rootId === false) {
$rootId = $table->addRoot();
}
$table->bind( $data_array );
$table->check();
$table->store();

 Inserting Node
$table = JTable::getInstance( 'yourtable' );
$table->setLocation( $reference_id, 'first-child' );
$table->bind( $data_array );
$table->id = 0;
$table->check();
$table->store();

 Basic Functions
$table->isLeaf $subtree = $table->getTree( $id ); $pathNodes = $table->getPath( $id ); $table->publish( $id,
$state, $userId )
$table->orderUp( $id ) $key = $this->_tbl_key; $reference_id = JRequest::getInt( 'reference' );
$this->$key = JRequest::getInt( 'id' ); $relation = 'last-child';
$delta = -2; $node_id = JRequest::getInt( 'id' );
$table->move( $delta ); $table->moveByReference( $reference_id, $relation, $node_id );
$table->delete( $node_id )

AGENDA

NESTED SETS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
lft, rgt

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Root Node
SELECT *
FROM Orgchart
WHERE lft = 1;

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Leaf Node (PHP check in J)
SELECT *
FROM Orgchart
WHERE(rgt - lft) = 1;

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
SELECT *
FROM Orgchart
WHERE lft = (rgt-1);

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
SELECT a, b, c
FROM Orgchart
WHERE lft = (rgt-1);

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Total Nodes (not in
J)

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Total Nodes (not in
J)
((rgt – lft)+1) / 2

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Subordinates
SELECT Mgrs.name AS manager, Workers.name AS worker
FROM Orgchart AS Mgrs, Orgchart AS Workers
WHERE Workers.lft > Mgrs.lft AND Workers.lft < Mgrs.rgt;

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Level of node (J has info in
row)
SELECT O2.name, COUNT(O1.name) AS level
FROM OrgChart AS O1, OrgChart AS O2
WHERE O2.lft BETWEEN O1.lft AND O1.rgt
GROUP BY O2.name;

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Maximum Height of Tree
SELECT MAX( hlevel ) AS height
FROM (
SELECT 02.name, COUNT( O1.id ) -1 AS hlevel
FROM OrgChart AS O1, OrgChart AS O2
GROUP BY O2.id
) AS L1

BASIC FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Age of Child Node
SELECT Workers.name
FROM OrgChart AS Mgrs, OrgChart AS Workers
WHERE Mgrs.lft = 2
AND Workers.lft = Mgrs.lft + 1;

AGENDA

ADVANCED FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
Path between Nodes (J is path to
root)
SELECT O2.name, (SELECT COUNT(*)
FROM OrgChart AS O4
AND O2.lft BETWEEN O4.lft AND O4.rgt) AS path_nbr
FROM OrgChart AS O1, OrgChart AS O2, OrgChart AS O3
WHERE O1.lft = 2
AND O3.lft = 19
AND O2.lft BETWEEN O1.lft AND O1.rgt
AND O3.lft BETWEEN O2.lft AND O2.rgt;

ADVANCED FUNCTIONS
Children to Parent
 Mom dies and Grandma adopts the kids.
 In effect the position itself is removed.
 This is a vertical promotion of an entire subtree.
Child node to the deleted node’s
position
 Give the business to the oldest son.
 The problem is that when the son is promoted,
this leaves a vacancy in his former position.
Deleting Nodes (J is simple (?))

ADVANCED FUNCTIONS
Sibling moves over to the vacant
position
 Dad dies and his oldest brother takes over the
business.
 This assumes that there is such a brother to take
the vacant position.

ADVANCED FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
JOOMLADAY NETHERLANDS 2013 - ELI ASCHKENASY - THEMODULARWAY 29
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22
// Delete the node and all of its children.
$query = $this->_db->getQuery(true);
$query->delete();
$query->from($this->_tbl);
$query->where('lft BETWEEN ' . (int) $node->lft . ' AND ' . (int) $node->rgt);
$this->_runQuery($query, 'JLIB_DATABASE_ERROR_DELETE_FAILED');
// Compress the left values.
$query->update($this->_tbl);
$query->set('lft = lft - ' . (int) $node->width);
$query->where('lft > ' . (int) $node->rgt);
// Compress the right values.
$query->update($this->_tbl);
$query->set('rgt = rgt - ' . (int) $node->width);
$query->where('rgt > ' . (int) $node->rgt);

ADVANCED FUNCTIONS
 Find width of subtree: (rgt-lft)+1
 Find offset of subtree: (old lft-new left)
 Store original lft
 Add width to lft and rgt where lft>=new left (creating gap)
 Change lft and rgt of subtree to lft-offset and rgt-offset where lft between cur_lft and cur_left+width
(filling gap)
 Subtract width from lft and rgt where lft>=new lft+width (connecting right)
Moving Subtrees (J is simple)

ADVANCED FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5 6 7
8 9
1
0
1
1
1
2
1
3
1
4
1
5
1
8
1
9
1
7
1
6
2
0
21
22

ADVANCED FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 9
1
0
1
5
1
6
1
7
1
8
1
9
2
2
2
3
2
1
2
0
2
4
21
22
1
1
1
2
1
3
1
4
width = (16-13)+1 = 4
orig_lft = 13
offset = (orig_lft-new_lft)+width = 12

ADVANCED FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5
1
0
1
5
1
6
2
2
2
3
2
1
2
4
21
22
1
1
1
2
1
3
1
4
6 7
89
width = (16-13)+1 = 4
orig_lft = 13

ADVANCED FUNCTIONS
Terry Earls
Charlotte
Weiss
Rob
Walters
Manuel
Oliveira
Dan
Wilson
Chen
Yang
Phyllis
Harris
Mark
Hanson
Maureen
Magnotta
Patricia
Doyle
Mike
Nash
1
2
3 4 5
1
0
1
5
1
6
1
8
1
9
1
7
2
0
21
22
1
1
1
2
1
3
1
4
6 7
89
width = (16-13)+1 = 4
orig_lft = 13

AGENDA
 The Ten Commandments

TEN COMMANDMENTS
 I am not the Lord thy God, test on your own
 Thou shalt think if Nested Sets are what you
need
 Thou shalt utilize native Joomla! if adequate
 Thou must add index to rgt
 Honor thy table locks
 Thou shalt think about a-synch data
 Thou shalt separate entities from hierarchy
 Hierarchy Leafs are still categories (Thou shalt)
 Thou shalt allow entities belonging to many
nodes

HET EINDE
ja, ik spreek vloeiend nederlands...

MySQL Nested Datasets #JDNL13

More Related Content

Viewers also liked (9)

Similar to MySQL Nested Datasets #JDNL13 (20)

Recently uploaded (20)

MySQL Nested Datasets #JDNL13