I want to switch from MongoDb to convex in Node Js project. How should I start?

Please help

30 Replies

Welcome! If the data needs to be preserved, and especially if it's a live application with users, you can start by streaming your data into Convex without disrupting the existing data. That way you can start experimenting with rewriting some of your backend against real data. Docs here: https://docs.convex.dev/database/import-export/streaming#streaming-import

Streaming Data in and out of Convex | Convex Developer Hub

Streaming Data in and out of Convex

beingkartikOP•12mo ago

Is there any example github repo for node js?

erquhart•12mo ago

Even better, there's a quickstart: https://docs.convex.dev/quickstart/nodejs If you specifically want an example, there's a node chat app example repo too: https://github.com/get-convex/convex-node-starter

beingkartikOP•12mo ago

Is it necessary to create functions to store data?

erquhart•12mo ago

I haven't used streaming imports myself but I don't believe it requires writing convex functions. You would use Airbyte to connect to your mongo db as a source and your convex deployment as a destination

beingkartikOP•12mo ago

How can we define functions manually on dashboard?

erquhart•12mo ago

If you want to run a function from the dashboard you'll still need to define it in code locally. With npx convex dev running, your local functions are automatically pushed to your development environment in Convex and will appear on the dashboard.

beingkartikOP•12mo ago

I have create a function called addUser and now in controller folder I am using it like this

    const user = await convex.mutation('addUser', {
      first_name,
      last_name,
      email,
      phone_number,
      role: role.toLowerCase(),
      is_active: true,
      hashedPassword,
    })

    const user = await convex.mutation('addUser', {
      first_name,
      last_name,
      email,
      phone_number,
      role: role.toLowerCase(),
      is_active: true,
      hashedPassword,
    })

but its showing Argument of type 'string' is not assignable to parameter of type 'FunctionReference<"mutation">'.

erquhart•12mo ago

convex.mutation() requires a reference to a convex mutation rather than just the string name. You'll want to import api from ../convex/_generated/api (replace ../convex with the path to your convex directory). Convex functions are accessed through the api object based on their path. For example, if your addUser mutation is defined in convex/user.ts, you would call it as:

const user = await convex.mutation(api.user.addUser, { ...args })

const user = await convex.mutation(api.user.addUser, { ...args })

Example line from the node starter repo: https://github.com/get-convex/convex-node-starter/blob/1c0e9f573ae5e123fe51bc2cc2b5c599f6a262c1/server.js#L19 And docs: https://docs.convex.dev/functions/mutation-functions#calling-mutations-from-clients

beingkartikOP•12mo ago

@erquhart I think i should not use convex on node Js server I have because convex itself is a server. Am I right?

erquhart•12mo ago

If you can avoid it, definitely Life is much easier lol

beingkartikOP•12mo ago

Lol. Can you tell me the issues I can face If I do ?

erquhart•12mo ago

I wouldn't expect issues per se, you just have two backend systems instead of one. It also depends on what you're using the node service for.

beingkartikOP•12mo ago

I have all my endpoints on node js server which are interacting with the DB

erquhart•12mo ago

There's a ton of value in your application client working directly with the Convex service, getting realtime data, etc If you're migrating an existing app, effectively switching out your database for Convex while still using your node service is a forward move. From there you can continue toward working directly against the Convex service over time. Did you try streaming import yet?

beingkartikOP•12mo ago

You mean I should use convex on the client side? Not yet

erquhart•12mo ago

Calling Convex direct from your client is a primary use case for Convex, it enables realtime data in your client with minimal latency. But if you have an existing app you may not be able to use it from your client right away, in which case you'll want to determine a migration path, or at least an experimentation path to start.

beingkartikOP•12mo ago

gotcha. Thankyou Hey @erquhart While creating a mutation function how can i create args optional? email: v.string().optional(), title: v.string().optional(), url: v.string().optional(), I am trying this but its throwing error

erquhart•12mo ago

Hey! You’re close, just have to wrap the optional type:

v.optional(v.string())

v.optional(v.string())

erquhart•12mo ago

Good breakdown of how to use the different validators here: https://docs.convex.dev/database/schemas#validators

Schemas | Convex Developer Hub

Schema validation keeps your Convex data neat and tidy. It also gives you end-to-end TypeScript type safety!

beingkartikOP•12mo ago

export const processInteractiveVideo = action({
  args: {
    videoId: v.string(),
  },
  handler: async (ctx,args) => {

    const videoData = //TODO: I want to query the video data using args.videoId
    
    const response = await fetch(
      `http://backend-dev:8000/web-ui-process-data`,
      {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify(videoData),
      }
    );

    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }

    const processedData = await response.json();
  },
});

export const processInteractiveVideo = action({
  args: {
    videoId: v.string(),
  },
  handler: async (ctx,args) => {

    const videoData = //TODO: I want to query the video data using args.videoId
    
    const response = await fetch(
      `http://backend-dev:8000/web-ui-process-data`,
      {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify(videoData),
      }
    );

    if (!response.ok) {
      throw new Error(`HTTP error! status: ${response.status}`);
    }

    const processedData = await response.json();
  },
});

I have created this action and i want to perform a query inside it to find the video data using video id. How can I perform this? @erquhart

erquhart•12mo ago

I fed your question into the AI chat in the Convex docs and it did a pretty great job answering: --- In your action, use the runQuery field of the action context (ctx) to call a query that performs the read operation on the desired video data. This process will look like as follows: 1. First, create an internal query that fetches video data based on the video id:

export const fetchVideo = internalQuery({
  args: { id: v.id("videos") },
  handler: async (ctx, arg) => {
    return await ctx.db.get(arg.id);
  },
});

export const fetchVideo = internalQuery({
  args: { id: v.id("videos") },
  handler: async (ctx, arg) => {
    return await ctx.db.get(arg.id);
  },
});

2. Reference this internal query in your action:

export const processInteractiveVideo = action({
  args: {
    videoId: v.string(),
  },
  handler: async (ctx,args) => {
    const videoData = await ctx.runQuery(internal.videos.fetchVideo, {
      id: args.videoId,
    });
    
    // rest of your action logic follows...
  },
});

export const processInteractiveVideo = action({
  args: {
    videoId: v.string(),
  },
  handler: async (ctx,args) => {
    const videoData = await ctx.runQuery(internal.videos.fetchVideo, {
      id: args.videoId,
    });
    
    // rest of your action logic follows...
  },
});

This way, you're calling the fetchVideo query inside your action using the runQuery method. The videoId is provided as an argument to the query and the resulting video data is used in your function.
Do not forget to replace "videos" with the actual schema name for videos in your database if it's different.

beingkartikOP•12mo ago

This is so cool, Thankyou Where can i see the logs if I want to log something inside action

erquhart•12mo ago

Logs from your convex code print in the dashboard logs section You can also pass the --tail-logs flag to npx convex dev to get logs in your CLI if your action is running in the dev environment.

beingkartikOP•12mo ago

where should i pass this --tail-logs?

erquhart•12mo ago

Or you can run npx convex logs locally and get logs for any deployment, including production, just have to specify which environment you want If you want this for dev locally, you would run npx convex dev --tail-logs to run the dev server and get logs in the same command

beingkartikOP•12mo ago

message.txt

beingkartikOP•12mo ago

hey @erquhart How can I use query function in python code to query the data?

erquhart•12mo ago

There's a python page in the docs that should get you going: https://docs.convex.dev/client/python

Python | Convex Developer Hub

See the Python Quickstart and the

erquhart•12mo ago

You can also search for most of what you need in the Convex Search app, it searches across Discord, Stack, and the docs: https://search.convex.dev

Convex Developer Search

Search Docs, Stack, Discord all at once

I want to switch from MongoDb to convex in Node Js project. How should I start?

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