Writing data to Database | Next.js Supabase SaaS Kit

Learn how to write, update and delete data using the Supabase Database in Next.js Supabase SaaS project

Similarly to reading data, we may want to create a custom hook also when we write, update or delete data to our Supabase database.

Assuming we have an entity called tasks, and we want to create a hook to create a new Task, we can do the following.

First, we create a new hook at lib/tasks/hooks/use-create-task.ts
We add the tasks table name to lib/db-tables.ts
We create a mutations.ts file within lib/tasks

export const TASKS_TABLE = `tasks`;

In our mutations file, we will add all the mutations we want to perform on the tasks table. In this case, we will add a createTask mutation.

import type { SupabaseClient } from '@supabase/supabase-js';
import type { Database } from '../../database.types';
import type Task from '~/lib/tasks/types/task';
import { TASKS_TABLE } from '~/lib/db-tables';
type Client = SupabaseClient<Database>;
export function createTask(client: Client, task: Omit<Task, 'id'>) {
  return client.from(TASKS_TABLE).insert({
    name: task.name,
    organization_id: task.organizationId,
    due_date: task.dueDate,
    done: task.done,
  });
}

Calling mutation using a Server Action

The best way to call a mutation is to use a Next.js Server Action. This way, we can use the revalidatePath function to revalidate the page that we want to revalidate after the mutation is completed.

'use server';
import { revalidatePath } from 'next/cache';
import { createTask } from '~/lib/tasks/mutations';
import type Task from '~/lib/tasks/types/task';
import { withSession } from '~/core/generic/actions-utils';
import getSupabaseServerActionClient from '~/core/supabase/action-client';
type CreateTaskParams = {
  task: Omit<Task, 'id'>;
  csrfToken: string;
};
export const createTaskAction = withSession(
  async (params: CreateTaskParams) => {
    const client = getSupabaseServerActionClient();
    await createTask(client, params.task);
    revalidatePath('/dashboard/[organization]/tasks');
  }
);

Then, we call the action from a form:

'use client';
import type { FormEventHandler } from 'react';
import { useCallback, useTransition } from 'react';
import { toast } from 'sonner';
import { useRouter } from 'next/navigation';
import TextField from '~/core/ui/TextField';
import Button from '~/core/ui/Button';
import If from '~/core/ui/If';
import useCurrentOrganization from '~/lib/organizations/hooks/use-current-organization';
import { createTaskAction } from '~/lib/tasks/actions';
import useCsrfToken from '~/core/hooks/use-csrf-token';
const CreateTaskForm = () => {
  const [isMutating, startTransition] = useTransition();
  const organization = useCurrentOrganization();
  const organizationId = organization?.id as number;
  const csrfToken = useCsrfToken();
  const router = useRouter();
  const onCreateTask: FormEventHandler<HTMLFormElement> = useCallback(
    async (event) => {
      event.preventDefault();
      const target = event.currentTarget;
      const data = new FormData(target);
      const name = data.get('name') as string;
      const dueDate = (data.get('dueDate') as string) || getDefaultDueDate();
      if (name.trim().length < 3) {
        toast.error('Task name must be at least 3 characters long');
        return;
      }
      const task = {
        organizationId,
        name,
        dueDate,
        done: false,
      };
      startTransition(async () => {
        await createTaskAction({ task, csrfToken });
        router.push('../tasks');
      });
    },
    [csrfToken, organizationId, router]
  );
  return (
    <form onSubmit={onCreateTask}>
      <div className={'flex flex-col space-y-2'}>
        <TextField.Label>
          Name
          <TextField.Input
            required
            name={'name'}
            placeholder={'ex. Launch on IndieHackers'}
          />
          <TextField.Hint>Hint: whatever you do, ship!</TextField.Hint>
        </TextField.Label>
        <TextField.Label>
          Due date
          <TextField.Input name={'dueDate'} type={'date'} />
        </TextField.Label>
        <div
          className={
            'flex flex-col space-y-2 md:flex-row md:space-x-2 md:space-y-0'
          }
        >
          <Button loading={isMutating}>
            <If condition={isMutating} fallback={<>Create Task</>}>
              Creating Task...
            </If>
          </Button>
          <Button color={'transparent'} href={'../tasks'}>
            Go back
          </Button>
        </div>
      </div>
    </form>
  );
};
function getDefaultDueDate() {
  const date = new Date();
  date.setDate(date.getDate() + 1);
  date.setHours(23, 59, 59);
  return date.toDateString();
}
export default CreateTaskForm;

Calling mutation using SWR

Alternatively, we can use the createTask mutation in our useCreateTask hook.

We will be using the useSWRMutation hook from swr to create our hook.

lib/tasks/hooks/use-create-task.ts

import useSWRMutation from 'swr/mutation';
import { useRouter } from 'next/navigation';
import useSupabase from '~/core/hooks/use-supabase';
import { createTask } from '~/lib/tasks/mutations';
import type Task from '~/lib/tasks/types/task';
function useCreateTaskMutation() {
 const client = useSupabase();
 const router = useRouter();
 const key = 'tasks';
 return useSWRMutation(key, async (_, { arg: task }: { arg: Omit<Task, 'id'> }) => {
   return createTask(client, task);
 }, {
   onSuccess: () => router.refresh()
 });
}
export default useCreateTaskMutation;

Let's take a look at a complete example of a form that makes a request using the hook above:

components/tasks/CreateTaskForm.tsx

import { useRouter } from 'next/router';
import type { FormEventHandler } from 'react';
import { useCallback } from 'react';
import { toast } from 'sonner';
import TextField from '~/core/ui/TextField';
import Button from '~/core/ui/Button';
import useCreateTaskMutation from '~/lib/tasks/hooks/use-create-task';
import useCurrentOrganization from '~/lib/organizations/hooks/use-current-organization';
const CreateTaskForm = () => {
 const createTaskMutation = useCreateTaskMutation();
 const router = useRouter();
 const organization = useCurrentOrganization();
 const organizationId = organization?.id as number;
 const onCreateTask: FormEventHandler<HTMLFormElement> = useCallback(
   async (event) => {
     event.preventDefault();
     const target = event.currentTarget;
     const data = new FormData(target);
     const name = data.get('name') as string;
     const dueDate = (data.get('dueDate') as string) || getDefaultDueDate();
     if (name.trim().length < 3) {
       toast.error('Task name must be at least 3 characters long');
       return;
     }
     const task = {
       organizationId,
       name,
       dueDate,
       done: false,
     };
     // create task
     await createTaskMutation.trigger(task);
     // redirect to /tasks
     return router.push(`/tasks`);
   },
   [router, createTaskMutation, organizationId]
 );
 return (
   <form onSubmit={onCreateTask}>
     <div>
       <TextField.Label>
         Name
         <TextField.Input
           required
           name={'name'}
           placeholder={'ex. Launch on IndieHackers'}
         />
         <TextField.Hint>Hint: whatever you do, ship!</TextField.Hint>
       </TextField.Label>
       <TextField.Label>
         Due date
         <TextField.Input name={'dueDate'} type={'date'} />
       </TextField.Label>
       <div>
         <Button>Create Task</Button>
       </div>
     </div>
   </form>
 );
};
export default CreateTaskForm;
function getDefaultDueDate() {
 const date = new Date();
 date.setDate(date.getDate() + 1);
 date.setHours(23, 59, 59);
 return date.toDateString();
}