Creating a Tree

FlexTree is a tree storage repository based on the Left-Right Value algorithm. Trees are persisted in database tables, so creating a tree means creating a database table that follows a set of format conventions.

Table Structure

By default, FlexTree requires every tree table to have at least the following fields

Field Name	Data Type	Description
id	number	Primary key
name	string	Node name
level	number	Node level; 0 indicates the root node, 1-N indicates the Nth level
leftValue	number	Left value
rightValue	number	Right value
treeId	number	Optional; used to distinguish different trees in a multi-tree table

Creating the Table

The database table that stores the tree is created by the application itself; FlexTree does not create the database table.

Generally, you can create it with SQL like the following:

    CREATE TABLE IF NOT EXISTS  org (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        name VARCHAR(60),  
        level INTEGER,  
        leftValue INTEGER, 
        rightValue INTEGER,
        -- Other fields

If you are using prisma, you can also declare the model like this:

model Org {
  id            Int    @id @default(autoincrement())
  name          String?
  treeId        Int?
  level         Int?
  leftValue     Int?
  rightValue    Int? 
 //   Other fields       
}

Customization

By default, a tree table is required to have the five key fields id, level, leftValue, rightValue, and name. To store multiple trees in a single table, you additionally need the treeId field.

If you want to customize the key fields — including their types, for example using uuid as the primary key — FlexTree fully supports customization.

See the Customization section for details.