# typeorm-pg-adjacency-list-tree
> A library that allows to use an adjacency list tree with typeorm and postgres
Latest version **2.0.0** (published 2023-12-13) · MIT license · 0 weekly downloads
## Install
```sh
npm install typeorm-pg-adjacency-list-tree
pnpm add typeorm-pg-adjacency-list-tree
yarn add typeorm-pg-adjacency-list-tree
bun add typeorm-pg-adjacency-list-tree
```
## Health
**Score 25/100 (F)** — status: abandoned.
Positive: has types; no vulnerabilities; high quality score.
Warnings: low downloads; no esm support.
Negative: abandoned; low maintenance score.
## Facts
| | |
|---|---|
| Version | 2.0.0 |
| Published | 2023-12-13 |
| First published | 2022-02-07 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | CommonJS |
| Dependencies | 1 |
| Unpacked size | 150.3 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 7 |
| Author | slaviqueue |
| Maintainers | slaviqueue |
| Keywords | typeorm, adjacency-list, postgres-adjacency-list, typeorm-adjacency-list |
## Links
- npm: https://www.npmjs.com/package/typeorm-pg-adjacency-list-tree
- Repository: https://github.com/slaviqueue/typeorm-pg-adjacency-list-tree
- Issues: https://github.com/slaviqueue/typeorm-pg-adjacency-list-tree/issues
- npm.io page: https://npm.io/package/typeorm-pg-adjacency-list-tree
## Dependencies (1)
- [lodash](https://npm.io/package/lodash.md) ^4.17.21
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## Recent versions
- 2.0.0 (latest) — 2023-12-13
- 1.1.0 — 2022-02-13
- 1.0.6 — 2022-02-07
## README
# typeorm-pg-adjacency-list-tree
[](https://github.com/slaviqueue/typeorm-pg-adjacency-list-tree/actions)
[](https://www.npmjs.com/package/typeorm-pg-adjacency-list-tree)
This library helps to manage trees that are structured as as adjacency list in
postgres.
It partially implements public interface of `TreeRepository` from typeorm. Check
[tree-repository.interface.ts](https://github.com/slaviqueue/typeorm-pg-adjacency-list-tree/blob/master/lib/repository/tree-repository.interface.ts)
Current version of the library is compatible with typeorm >= 0.3.0. If you use
typeorm < 0.3.0, please use typeorm-pg-adjacency-list-tree < 2.0.0.
## Installation
```bash
npm i typeorm-pg-adjacency-list-tree
```
## Quick start
### Decorators
There are three decorators exported from this module: `Tree`, `TreeParent` and
`TreeChildren`.
`Tree` is used to specify that decoratable entity is a tree.
```typescript
@Tree()
@Entity()
export class Node {
@PrimaryGeneratedColumn()
public id!: number
@Column()
public value!: number
}
```
`TreeParent` is used to identify class property which will hold entities parent:
```typescript
@Tree()
@Entity()
export class Node {
@PrimaryGeneratedColumn()
public id!: number
@TreeParent()
public parent!: Node
@Column()
public value!: number
}
```
`TreeChildren` is used to identify class property which will hold children of
current entity:
```typescript
@Tree()
@Entity()
export class Node {
@PrimaryGeneratedColumn()
public id!: number
@TreeParent()
public parent!: Node
@TreeChildren()
public children!: Node[]
@Column()
public value!: number
}
```
### Tree repository
In the latest major version of typeorm, they decided to drop support for
creating custom repositories with classes. And now the only way to create a
custom repository is to call `dataSource.getRepository(Entity).extend({ /* your custom repo here */ })`.
To simplify the process of getting the tree repo, there's a helper function
`extendTreeRepository`.
If you have any suggestions on how to implement this in a better way, please
create an issue or send a pr.
Instantiating a tree repo from connection:
```typescript
import { extendTreeRepository } from 'typeorm-pg-adjacency-list-tree'
const nodeRepo = extendTreeRepository(dataSource.getRepository(Node))
const roots = await nodeRepo.findRoots()
```
After 0.3, extending a tree repo is not as simple as just extending a class.
We have to get our tree repository first.
```typescript
import { extendTreeRepository } from 'typeorm-pg-adjacency-list-tree'
const userRepo = extendTreeRepository(dataSource.getRepository(User)).extend({
async getByName(name: string) {
return this.find({ where: { name } })
},
})
```
### Tree repository methods
```typescript
findTrees(options?: FindTreeOptions): Promise
```
Gets complete trees for all roots in the table.
```typescript
findRoots(options?: FindTreeOptions): Promise
```
Roots are entities that have no ancestors. Finds them all.
```typescript
findDescendants(entity: Entity, options?: FindTreeOptions): Promise
```
Gets all children (descendants) of the given entity. Returns them all in a flat array.
```typescript
findDescendantsTree(entity: Entity, options?: FindTreeOptions): Promise
```
Gets all children (descendants) of the given entity. Returns them in a tree - nested into each other.
```typescript
countDescendants(entity: Entity): Promise
```
Gets number of descendants of the entity.
```typescript
createDescendantsQueryBuilder(alias: string, entity: Entity): Promise>
```
Creates a query builder used to get descendants of the entities in a tree.
```typescript
findAncestors(entity: Entity, options?: FindTreeOptions): Promise
```
Creates a query builder used to get descendants of the entities in a tree.
```typescript
findAncestorsTree(entity: Entity, options?: FindTreeOptions): Promise
```
Gets all parents (ancestors) of the given entity. Returns them in a tree - nested into each other.
```typescript
countAncestors(entity: Entity): Promise
```
Gets number of ancestors of the entity.
```typescript
createAncestorsQueryBuilder(alias: string, entity: Entity): Promise>
```
Creates a query builder used to get ancestors of the entities in the tree.
---
_Source: https://npm.io/package/typeorm-pg-adjacency-list-tree · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._