https://github.com/nineinchnick/closure-table-manager

PHP library that helps maintain adjacency list SQL structures
https://github.com/nineinchnick/closure-table-manager

Last synced: 23 days ago
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PHP library that helps maintain adjacency list SQL structures

• Host: GitHub
• URL: https://github.com/nineinchnick/closure-table-manager
• Owner: nineinchnick
• License: mit
• Created: 2014-02-16T13:15:07.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2014-07-08T12:27:55.000Z (over 10 years ago)
• Last Synced: 2024-04-23T23:46:34.495Z (7 months ago)
• Language: PHP
• Size: 191 KB
• Stars: 10
• Watchers: 4
• Forks: 2
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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closure-table-manager

=====================

PHP library that helps maintain adjacency list SQL structures.

TL;DR: It allows fetching all ancestors/descendants (indirect parents/children) in a single query, without using recursive queries.

Inspired by:

* [SQL::Tree Perl module](https://github.com/mlawren/sqltree)

* http://www.depesz.com/index.php/2008/04/11/my-take-on-trees-in-sql/

Currently supported databases:

* PostgreSQL

* SQLite 3

* MySQL and MariaDB

Pull requests with other databases support are very welcome.

## Installation

Using composer:

~~~bash

curl -sS https://getcomposer.org/installer | php

./composer.phar require nineinchnick/closure-table-manager:dev-master

~~~

## Usage

Call `Manager::getQueries()` to get an array of SQL queries that create a helper table to store ancestor/descendant relationships from the main table and triggers that maintain it.

When installed, triggers will block the following operations:

* Changing the primary key value

* Creating loops

A command line script is provided:

~~~

Usage: ./vendor/bin/closureTable.php [options] [operands]

Options:

  -d, --dsn          DSN connection string or just the driver name (pgsql, sqlite, mysql).

  -t, --table        Table name.

  -p, --parent       Parent foreign key column name.

  -i, --pk           Primary key column name.

  --pk_type           Primary key and parent column type.

  --path             Path column name; if set, additional triggers will be generated.

  --path_from        Column which value will be used to build a path. Its values cant't contain path_separator.

  --path_separator   Path separator character.

  --table_suffix     Suffix of the closure table.

~~~

## Example

Having the following tables:

~~~sql

CREATE TABLE products (

  id INTEGER,

  category_id INTEGER NOT NULL REFERENCES categories (id),

  -- ...

  PRIMARY KEY(id)

);

CREATE TABLE categories (

  id INTEGER,

  parent_id INTEGER NOT NULL REFERENCES categories (id),

  -- ...

  PRIMARY KEY(id)

);

~~~

It is quite common to ask database for all products in given category and it's subcategories.

~~~sql

    SELECT p.*

      FROM products p

INNER JOIN categories_tree c on p.category_id = c.id

     WHERE c.parent_id = ;

~~~

When user is _in_ some category, we would like to show him _path_ to this category. So he could easily move to some parent category.

~~~sql

    SELECT c.*

      FROM categories c

INNER JOIN categories_tree t on c.id = t.parent_id

     WHERE c.id = 4

  ORDER BY t.depth DESC;

~~~