Writing data to Database

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.

1. First, we create a new hook at lib/tasks/hooks/use-create-task.ts
2. We add the tasks table name to lib/db-tables.ts
3. 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.

export function createTask(
  client: Client,
  task: Task,
) {
  return client.from(TASKS_TABLE).insert(task).throwOnError();
}

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

We will be using the useMutation hook from react-query to create our hook.

function useCreateTaskMutation(task: Task) {
  const client = useSupabase();

  return useMutation(
    async (task: Task) => {
      return createTask(client, task);
    }
  );
}

export default useCreateTaskMutation;

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

import { useNavigate } from '@remix-run/react';
import type { FormEventHandler } from 'react';
import { useCallback } from 'react';
import toaster from 'react-hot-toast';

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 navigate = useNavigate();
  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) {
        toaster.error('Task name must be at least 3 characters long');

        return;
      }

      const task = {
        organizationId,
        name,
        dueDate,
        done: false,
      };

      // create task
      await createTaskMutation.mutateAsync(task);

      // redirect to /tasks
      return navigate(`/tasks`);
    },
    [navigate, 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();
}