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    orbit-db-tablestore

    0.0.15 • Public • Published

    orbit-db-tablestore

    Gitter npm version

    An indexed and remoted loaded datastore for orbit-db. Indexed fields are searchable and sortable.

    An orbit-db datastore that can be indexed and searched without downloading the entire dataset. Allows the creation of SQL-like tables. Access using ipfs-http-client.

    The goal is to be able to load and search large datasets quickly in a browser.

    Used in orbit-db.

    Table of Contents

    Install

    npm install orbit-db
    npm install orbit-db-tablestore
    npm install ipfs-http-client

    Usage

    First, create an instance of OrbitDB:

    const ipfsClient = require('ipfs-http-client')
    const OrbitDB = require('orbit-db')
    const TableStore = require('orbit-db-tablestore')
     
     
    const ipfs = ipfsClient({
        host: "localhost",
        port: 5001,
        protocol: 'http'
      })
     
    OrbitDB.addDatabaseType(TableStore.type, TableStore)
     
    const orbitdb = await OrbitDB.createInstance(ipfs)
     

    Creating a table

    Each table starts with a schema definition. Creating a schema defines the fields and indexes that will be created in the table. Multiple columns can be indexed and searched. Each index is implemented as a B-tree.

    The properties of an index are:

    • primary - This designates a column as the primary key. There should only be one.
    • type - The data type the column will hold. Supported values are 'string', 'number', and 'boolean'
    • unique - Whether the column has unique values.

    To create a table we'll start by creating a JS class that has a static getter named 'constraints'. It should also contain matching properties for every contraint defined.

    class Player {
     
        static get constraints() {
            return {
                id: { primary: true, unique:true, type: 'number' },
                name: { unique: false, type: 'string' },
                currentTeam: { unique: false, type: 'string' },
                battingHand: { unique: false, type: 'string' },
                throwingHand: { unique: false, type: 'string' }
            }
        }
     
        constructor() {
            this.id = null
            this.name = null
            this.currentTeam = null
            this.battingHand = null
            this.throwingHand = null
        }
        
    }
     
    /** Put in an async function **/
     
    let table = await orbitdb.open("testschema", {
        create: true, 
        type: "table"
    })
     
     
    //Create the schema. Only needs to be done when creating the table initially. 
    await table.createSchema(Player)
     

    Loading an existing table

    let store = await orbitdb.open(ADDRESS_OF_DATASTORE, {
        type: "table"
    })
     
    await store.load()
     

    Insert JSON objects into the table.

     await table.put(5, {
        id: 5,
        name: "Andrew McCutchen",
        currentTeam: "PIT",
        battingHand: "R",
        throwingHand: "R"
     
    await table.put(6, {
        id: 6,
        name: "Pedro Alvarez",
        currentTeam: "BAL",
        battingHand: "R",
        throwingHand: "R"
    })
     
    await table.put(8, {
        id: 8,
        name: "Jordy Mercer",
        currentTeam: "PIT",
        battingHand: "L",
        throwingHand: "R"
    })
     
     
    await table.put(9, {
        id: 9,
        name: "Doug Drabek",
        currentTeam: "BAL",
        battingHand: "L",
        throwingHand: "R"
    })
     
    • Note: The key and the primary key values should match.

    Query the table by the primary key

    let player = await table.get(9)
     
    console.log(player)
     
    //Prints 
    // {
    //     id: 9,
    //     name: "Doug Drabek",
    //     currentTeam: "BAL",
    //     battingHand: "L",
    //     throwingHand: "R",
    //     someOtherData: "day"
    // }

    Query the full list. Takes an offset and a limit as parameters

     
    let list = await table.list(0, 10) //offset 0, limit 10
     

    Query the table by the indexed fields. Returns an array with all matching values.

     
    let teamPIT = await table.getByIndex("currentTeam", "PIT", 100, 0) //100 is the limit and 0 is the offset
    let teamBAL = await table.getByIndex("currentTeam", "BAL", 100, 0)
     
    let battingR = await table.getByIndex("battingHand", "R", 100, 0)
    let battingL = await table.getByIndex("battingHand", "L", 100, 0)
     
    let throwingR = await table.getByIndex("throwingHand", "R", 100, 0)    
     

    Count the records

    let count = await table.count()

    Commit your changes.

    Your changes are persisted to disk when you call commit(). Before commit() the store will respond with the old data when queried. Multiple calls to "put" can be made inside the same transaction.

    Todo: There should be an auto-commit option somewhere.

    await table.commit()

    License

    MIT

    Install

    npm i orbit-db-tablestore

    DownloadsWeekly Downloads

    1

    Version

    0.0.15

    License

    MIT

    Unpacked Size

    52.4 kB

    Total Files

    15

    Last publish

    Collaborators

    • ptoner