README

在数据库表中对树结构进行存储的嵌套集合算法实现。

安装

通过 Composer 安装

composer require paulzi/yii2-nested-sets

或者将以下内容添加到您的 composer.json 文件的 require 部分：

"paulzi/yii2-nested-sets" : "^1.0"

到 require 部分

迁移示例

警告！depth 属性不能是无符号的！

单个树迁移

class m150722_150000_single_tree extends Migration
{
    public function up()
    {
        $tableOptions = null;
        if ($this->db->driverName === 'mysql') {
            // http://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci
            $tableOptions = 'CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE=InnoDB';
        }
        $this->createTable('{{%single_tree}}', [
            'id'    => Schema::TYPE_PK,
            'lft'   => Schema::TYPE_INTEGER . ' NOT NULL',
            'rgt'   => Schema::TYPE_INTEGER . ' NOT NULL',
            'depth' => Schema::TYPE_INTEGER . ' NOT NULL', // not unsigned!
            'name'  => Schema::TYPE_STRING . ' NOT NULL', // example field
        ], $tableOptions);
        $this->createIndex('lft', '{{%single_tree}}', ['lft', 'rgt']);
        $this->createIndex('rgt', '{{%single_tree}}', ['rgt']);
    }
}

多个树迁移

class m150722_150100_multiple_tree extends Migration
{
    public function up()
    {
        $tableOptions = null;
        if ($this->db->driverName === 'mysql') {
            // http://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci
            $tableOptions = 'CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE=InnoDB';
        }
        $this->createTable('{{%multiple_tree}}', [
            'id'    => Schema::TYPE_PK,
            'tree'  => Schema::TYPE_INTEGER . ' NULL',
            'lft'   => Schema::TYPE_INTEGER . ' NOT NULL',
            'rgt'   => Schema::TYPE_INTEGER . ' NOT NULL',
            'depth' => Schema::TYPE_INTEGER . ' NOT NULL', // not unsigned!
            'name'  => Schema::TYPE_STRING . ' NOT NULL', // example field
        ], $tableOptions);
        $this->createIndex('lft', '{{%multiple_tree}}', ['tree', 'lft', 'rgt']);
        $this->createIndex('rgt', '{{%multiple_tree}}', ['tree', 'rgt']);
    }
}

配置

use paulzi\nestedsets\NestedSetsBehavior;

/**
 * @property integer $id
 * @property integer $lft
 * @property integer $rgt
 * @property integer $depth
 *
 * @mixin NestedSetsBehavior
 */

class Sample extends \yii\db\ActiveRecord
{
    public function behaviors() {
        return [
            [
                'class' => NestedSetsBehavior::class,
                // 'treeAttribute' => 'tree',
            ],
        ];
    }

    public function transactions()
    {
        return [
            self::SCENARIO_DEFAULT => self::OP_ALL,
        ];
    }
}

您可以设置查询以查找根节点（可选）

class Sample extends \yii\db\ActiveRecord
{
    public static function find()
    {
        return new SampleQuery(get_called_class());
    }
}

查询类

use paulzi\nestedsets\NestedSetsQueryTrait;

class SampleQuery extends \yii\db\ActiveQuery
{
    use NestedSetsQueryTrait;
}

选项

• $treeAttribute = null - 为表模式中的多个树设置树属性。
• $leftAttribute = 'lft' - 表模式中的左属性。
• $rightAttribute = 'rgt' - 表模式中的右属性。
• $depthAttribute = 'depth' - 表模式中的深度属性（注意：它必须是带符号的整数）。

使用方法

选择

获取根节点

如果您连接 NestedSetsQueryTrait，则可以获取所有根节点

$roots = Sample::find()->roots()->all();

获取节点的祖先

获取节点的祖先

$node11 = Sample::findOne(['name' => 'node 1.1']);
$parents = $node11->parents; // via relation
$parents = $node11->getParents()->all(); // via query
$parents = $node11->getParents(2)->all(); // get 2 levels of ancestors

获取节点的父节点

$node11 = Sample::findOne(['name' => 'node 1.1']);
$parent = $node11->parent; // via relation
$parent = $node11->getParent()->one(); // via query

获取节点的根节点

$node11 = Sample::findOne(['name' => 'node 1.1']);
$root = $node11->root; // via relation
$root = $node11->getRoot()->one(); // via query

获取节点的后代

获取节点的所有后代

$node11 = Sample::findOne(['name' => 'node 1.1']);
$descendants = $node11->descendants; // via relation
$descendants = $node11->getDescendants()->all(); // via query
$descendants = $node11->getDescendants(2, true)->all(); // get 2 levels of descendants and self node
$descendants = $node11->getDescendants(3, false, true)->all(); // get 3 levels of descendants in back order

为节点及其后代填充 children 关系

$node11 = Sample::findOne(['name' => 'node 1.1']);
$tree = $node11->populateTree(); // populate all levels
$tree = $node11->populateTree(2); // populate 2 levels of descendants

获取节点的子节点

$node11 = Sample::findOne(['name' => 'node 1.1']);
$children = $node11->children; // via relation
$children = $node11->getChildren()->all(); // via query

获取叶子节点

获取节点的所有叶子

$node11 = Sample::findOne(['name' => 'node 1.1']);
$leaves = $node11->leaves; // via relation
$leaves = $node11->getLeaves(2)->all(); // get 2 levels of leaves via query

获取相邻节点

获取下一个节点

$node11 = Sample::findOne(['name' => 'node 1.1']);
$next = $node11->next; // via relation
$next = $node11->getNext()->one(); // via query

获取前一个节点

$node11 = Sample::findOne(['name' => 'node 1.1']);
$prev = $node11->prev; // via relation
$prev = $node11->getPrev()->one(); // via query

一些检查

$node1 = Sample::findOne(['name' => 'node 1']);
$node11 = Sample::findOne(['name' => 'node 1.1']);
$node11->isRoot() - return true, if node is root
$node11->isLeaf() - return true, if node is leaf
$node11->isChildOf($node1) - return true, if node11 is child of $node1

修改

创建根节点

$node11 = new Sample();
$node11->name = 'node 1.1';
$node11->makeRoot()->save();

注意：如果您允许多个树，并且未设置属性 tree，则自动取主键值。

将节点作为另一个节点的第一个子节点添加前缀

$node1 = Sample::findOne(['name' => 'node 1']);
$node11 = new Sample();
$node11->name = 'node 1.1';
$node11->prependTo($node1)->save(); // inserting new node

将节点作为另一个节点的最后一个子节点添加后缀

$node11 = Sample::findOne(['name' => 'node 1.1']);
$node12 = Sample::findOne(['name' => 'node 1.2']);
$node12->appendTo($node11)->save(); // move existing node

在另一个节点之前插入节点

$node13 = Sample::findOne(['name' => 'node 1.3']);
$node12 = new Sample();
$node12->name = 'node 1.2';
$node12->insertBefore($node13)->save(); // inserting new node

在另一个节点之后插入节点

$node13 = Sample::findOne(['name' => 'node 1.3']);
$node14 = Sample::findOne(['name' => 'node 1.4']);
$node14->insertAfter($node13)->save(); // move existing node

删除带有后代的节点

$node11 = Sample::findOne(['name' => 'node 1.1']);
$node11->delete(); // delete node, children come up to the parent
$node11->deleteWithChildren(); // delete node and all descendants