README.md•2.5 kB
# Welcome to your Convex functions directory!
Write your Convex functions here.
See https://docs.convex.dev/functions for more.
A query function that takes two arguments looks like:
```ts
// functions.js
import { query } from "./_generated/server";
import { v } from "convex/values";
export const myQueryFunction = query({
// Validators for arguments.
args: {
first: v.number(),
second: v.string(),
},
// Function implementation.
handler: async (ctx, args) => {
// Read the database as many times as you need here.
// See https://docs.convex.dev/database/reading-data.
const documents = await ctx.db.query("tablename").collect();
// Arguments passed from the client are properties of the args object.
console.log(args.first, args.second);
// Write arbitrary JavaScript here: filter, aggregate, build derived data,
// remove non-public properties, or create new objects.
return documents;
},
});
```
Using this query function in a React component looks like:
```ts
const data = useQuery(api.functions.myQueryFunction, {
first: 10,
second: "hello",
});
```
A mutation function looks like:
```ts
// functions.js
import { mutation } from "./_generated/server";
import { v } from "convex/values";
export const myMutationFunction = mutation({
// Validators for arguments.
args: {
first: v.string(),
second: v.string(),
},
// Function implementation.
handler: async (ctx, args) => {
// Insert or modify documents in the database here.
// Mutations can also read from the database like queries.
// See https://docs.convex.dev/database/writing-data.
const message = { body: args.first, author: args.second };
const id = await ctx.db.insert("messages", message);
// Optionally, return a value from your mutation.
return await ctx.db.get(id);
},
});
```
Using this mutation function in a React component looks like:
```ts
const mutation = useMutation(api.functions.myMutationFunction);
function handleButtonPress() {
// fire and forget, the most common way to use mutations
mutation({ first: "Hello!", second: "me" });
// OR
// use the result once the mutation has completed
mutation({ first: "Hello!", second: "me" }).then((result) =>
console.log(result),
);
}
```
Use the Convex CLI to push your functions to a deployment. See everything
the Convex CLI can do by running `npx convex -h` in your project root
directory. To learn more, launch the docs with `npx convex docs`.